10th Forum on New Materials
Poster presentations
ABSTRACTS
F:P01 DFT Mechanistic Pathways in Triphenylene Formation on Cu(111) using Benzene as LT-CVD Carbon Precursors for Energy Applications
O. TAU, N. LOVERGINE, P. PRETE, Department of Innovation Engineering, University of Salento, Lecce, Italy
Chemical vapor deposition (CVD) graphene is a key material for advanced technologies, owing to its unique combination of electrical conductivity, optical transparency, and mechanical flexibility. These properties make it highly attractive for applications ranging from energy devices—such as transparent electrode in solar cells as an alternative to conventional conductive oxides like ITO—to flexible electronics, sensors, and optoelectronic systems. Achieving high-quality CVD graphene at reduced temperatures with the aid of liquid aromatic hydrocarbons as precursors is therefore crucial to enable scalable integration on temperaturesensitive substrates [1,2]. This presentation reports on graphene nucleation investigated through DFT atomistic simulations, resolving the pathways of benzene precursor decomposition, surface diffusion, and C–C coupling on Cu(111). Benzene-derived phenyl species dominate the early-stage chemistry due to competing dehydrogenation and desorption, while progressive hydrogen depletion promotes carbon-rich conditions and irreversible bond formation. A complete pathway leading to triphenylene (C18H12), identified as a prototypical graphene nucleus, is revealed. Its formation is governed by the interplay between molecular topology, configurational flexibility, and surface coordination. These results highlight the key role of aromatic intermediates in enabling controlled graphene nucleation at reduced temperatures.
[1] O. Tau, N. Lovergine, P. Prete, Carbon, 206 (2023)142-149. https://doi.org/10.1016/j.carbon.2023.02.011; [2] O. Tau, N. Lovergine, P. Prete, Proc. of SPIE 13114 (2024) 1311409. https://doi.org/10.1117/12.3029561
F:P02 Modeling of Thermal Mismatch Induced Crack in Glass-ceramic Sealant of Solid Oxide Cell
YIFENG HONG, A. NEMATI, P. KHAJAVI, H. LUND FRANDSEN, Technical University of Denmark, Kongens Lyngby, Denmark
Thermal mismatches during the cooling of solid oxide cell (SOC) stacks induce substantial mechanical stresses in glass-ceramic sealants, leading to crack propagation and potential performance failure. This study presents a multiscale modeling framework that prioritizes both computational efficiency and model fidelity by integrating phase field fracture modeling with an improved sub-modeling strategy featuring a "sacrificial layer". This combined approach achieves a 95% reduction in calculation time (from 60h to 2.5h) while maintaining high accuracy compared to detailed full-scale models. The methodology was validated through four-point bending tests, showing excellent agreement with experimental load-displacement curves and crack patterns. Case studies demonstrate that sealant thickness exceeding 1500 um and thermal expansion coefficients (TEC) below 1e-6 1/K are critical determinants of fracture. These results are synthesized into physics-informed design maps, providing a robust guide for optimizing sealing solutions and enhancing the long-term operational stability of SOC stacks.
F:P03 Insights from Individual Atom Diffusivities in a Molecular Dynamics Simulation
Y. HINUMA, AIST, Ikeda, Osaka, Japan
Concerted migration is known as a mechanism that lowers the activation barrier of atom migration. Multiple atoms move concurrently in concerted migration, in contrast to a random walk style diffusion where atoms hop one at a time. The author points out that the statistical distribution of the individual diffusion coefficient of mobile atoms follows a universal curve under a random walk situation where diffusion follows Fick’s second law of diffusion. Molecular dynamics (MD) simulations based on a neural network potential (NNP) allows a sufficient number of diffusing atoms and a large enough diffusion coefficient that can distinguish random walker type diffusion from other types such as concerted migration. The distribution for alpha-AgI, which is concerted migration system as is well known, is clearly different from the universal curve. Ba1.75LiH2.7O0.9, a very fast hydride-ion conducting solid electrolyte with the K2NiF4-type layered structure [1], is not. Many H atoms are immobile, and the fraction of immobile atoms increases with decreasing temperature. Most mobile H follow the universal curve, implying a random walk situation, and some H atoms are very fast conductors.
[1]Takeiri, F. et al. Nat. Mater. 21, 325 (2022).
F:P04 Structure and Physical Properties of Phthalocyanine Derivatives in Langmuir Monolayers and Thin Films
A.V. KAZAK1,2,3, M.A. MARCHENKOVA2, I.V. RYKOV4, A.V. ROGACHEV5, T.V. DUBININA3,4, B.V. NABATOV2, V.V. BELYAEV6,7, V.A. AVDEENKOV7,8, A. ACHALKUMAR9,10, S. KUMAR11,12, 1Ivanovo State University, Ivanovo, Russia; 2A. V. Shubnikov Institute of Crystallography, Kurchatov Complex of Crystallography and Photonics, Moscow, Russia; 3Institute of Physiologically Active Substances, Russian Academy of Sciences, Chernogolovka, Russia; 4Lomonosov Moscow State University, Moscow, Russia; 5National Research Centre "Kurchatov Institute", Moscow, Russia; 6State University of Education, Moscow, Russia; 7RUDN University (Peoples’ Friendship University of Russia), Moscow, Russia; 8Synergy University, Moscow, Russia; 9Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati, Assam, India; 10Centre for Sustainable Polymers, Indian Institute of Technology Guwahati, Guwahati, Assam, India; 11Raman Research Institute, Bengaluru, India; 12Department of Chemistry, Nitte Meenakshi Institute of Technology, Yelahanka, India
Langmuir (L) films exhibit high degree of order and homogeneity. Film morphology is controlled by varying transfer conditions. Most precise methods to study structure of L-monolayers (LM) and L–Schaefer (LS) films are X-ray techniques. They provide info on external and internal structure of nanoscale objects, their dimensions, molecular arrangement, and internal architecture of density, structural inhomogeneity. LM were formed from chloroform solutions of compounds using Nima601A, KSV5000, and KSV2000 setups. Water purification systems were Millipore Elix 3 and Millipore Simplicity 185. Structure of floating monolayers was investigated using grazing-incidence diffraction and X-ray standing wave techniques at Langmuir beamline of Kurchatov Synchrotron Radiation Source. Thin films were fabricated by sequential monolayers transfer from water surface onto silicon and glass substrates using LS method. Surface topography and film thickness (n=1) deposited on silicon substrates were evaluated by AFM in semi-contact mode using Solver47 Pro microscope. Objects were phthalocyanine derivatives. We determined structure of resulting LM and thin films, investigated the physical properties of the resulting thin-film materials to develop new, highly efficient, low-defect thin-film materials.
The work is partially supported in frames of Indo-Russia Collaborative project Grant No.25-49-01022 from Russia Science Foundation and No. DST/IC/RSF/2025/1027 from the Department of Science and Technology, Government of India.
F:P05 Low-Resistivity Cu@Ag Flake-Based Pastes for HJT Solar Cell Electrodes Using Ag Complex Ink
JONG-HYUN LEE, JU JANG SEOUL, National University of Science and Technology, Seoul, Republic of Korea
Heterojunction with intrinsic thin layer (HJT) solar cells have emerged as a next-generation silicon photovoltaic technology owing to their high efficiency, excellent thermal stability, and bifacial power generation capability. However, their complex fabrication process and high production cost hinder large-scale commercialization. A practical approach to cost reduction is to replace conventional Ag-based interconnection pastes with Ag-coated Cu (Cu@Ag)-based alternatives, which must retain low electrical resistivity after annealing. In this study, a novel Ag complex-based ink formulation incorporating Cu@Ag flakes was developed. The ink was designed to induce in situ formation of Ag nanoparticles and promote their sintering with Cu@Ag flakes at 200 °C in air, forming a highly conductive electrode network. Systematic optimization of the composition was conducted by varying the types and ratios of Ag salts and solvent systems, along with suitable chelating and functional additives. The optimized paste achieved excellent electrical performance, exhibiting a specific resistivity on the order of 10⁻⁵ Ω·cm after annealing at 200 °C. These results demonstrate the potential of this Cu@Ag flake-containing paste as a cost-effective alternative for HJT solar cell metallization.
F:P06 DFT Studies of Bi Enhanced SrTiO3 Heterostructures for Photostimulated Hydrogen Production
D. GRYAZNOV1, E.A. KOTOMIN1, G. ZVEJNIEKS1, L.L. RUSEVICH1, N. DANEU2, S. ROOJ2,3, M.M. KRŽMANC2, 1Institute of Solid State Physics, University of Latvia, Riga, Latvia; 2Advanced Materials Department, Jožef Stefan Institute, Ljubljana, Slovenia; 3Jožef Stefan Institute, Ljubljana, Slovenia
SrTiO₃ and Bi₄Ti₃O₁₂ are promising materials for sustainable hydrogen production via photocatalysis due to their excellent catalytic properties and structural versatility. The layered Bi4Ti3O12 structure promotes the growth in two-dimensional (2D) morphology, while the symmetrical crystal structure of SrTiO3 does not facilitate the spontaneous formation of 2D nanostructures. However, due to their structural similarity, combined with favourable dissolution and transformation chemistries under hydrothermal conditions, Bi4Ti3O12 template nanoplatelets can gradually transform into SrTiO3 nanoplatelets leading to materials with ehnaced photocatalytic performance. This study investigates the electronic and geometric properties of such materials using hybrid DFT calculations as implemented in Crystal23. In particular, we have demonstrated the band gap decrease with Bi incorporation into SrTiO3 resulting in either SrTiO₃/Bi₄Ti₃O₁₂ heterostructure or BiO monolayer in SrTiO3 models. The theoretical studies are supported by the atomic scale characterization of the SrTiO3/Bi4Ti3O12 and SrTiO3 nanoplatelets.
F:P07 Hydrogen Production through Photoelectrocatalytic Water Splitting with WS₂/WO₃ Heterojunctions
M. CIFRE HERRANDO1, G. ROSELLÓ MÁRQUEZ2, J. GARCÍA ANTÓN1, 1Grupo de Ingeniería Electroquímica y Corrosión (IEC), Instituto ISIRYM, Universitat Politècnica de València, Valencia, Spain; 2Departamento de Ingeniería Química, Universitat de València, Burjassot, Valencia, Spain
The global energy crisis persists due to fossil fuel dependence, whose depletion and pollution risks demand clean alternatives. Hydrogen is a promising candidate, with photoelectrochemical (PEC) water splitting emerging as a viable solar-based method for sustainable H₂ production. Tungsten oxide (WO₃) stands out as a photoanode in PEC systems for its good conductivity, charge transfer efficiency, stability in acidic media, resistance to photocorrosion, and visible light absorption. To boost its performance, heterojunctions with materials like transition metal dichalcogenides (TMDs) are explored. WS₂, in particular, has shown potential to enhance WO₃'s photoelectrocatalytic activity. This study investigates the formation of WS₂/WO₃ heterojunctions to improve PEC performance. WO₃ nanostructures were synthesized via electrochemical anodization in acidic electrolyte under hydrodynamic conditions, followed by annealing at 600 °C. WS₂ nanosheets were produced by sonicating WS₂ powder, then deposited on WO₃ via electrophoretic deposition with varied durations. The samples were characterized by FE-SEM (morphology) and EIS (photoelectrochemical properties), then tested as photoanodes in PEC water splitting to evaluate hydrogen production via photocurrent density.
F:P08 Preparation and Electrochemical Performance of Ni Nanoparticle by Electro-explosion Method for Hydrogen Production
I-MING HUNG1,2, YAN-RONG CHEN1, DEBABRATA MOHANTY1, 1Department of Chemical Engineering and Materials Science, Yuan Ze University, Taoyuan City, Taiwan; 2Hierarchical Green-Energy Materials (Hi-GEM) Research Center, National Cheng Kung University, Tainan, Taiwan
Hydrogen is acknowledged as one of the primary candidate energy sources to replace fossil fuels in the future, possessing the advantages of being clean and renewable. Currently, hydrogen production methods are diverse, among which alkaline water electrolysis represents a mature and widely utilized technology. The hydrogen produced during this process is commonly referred to as “green hydrogen.” This study employs the wire electro-explosion method to prepare nickel nanoparticles in deionized water. The advantages of this method include simplicity, high efficiency, rapidity, and the reduction of chemical reagents, thereby minimizing environmental impact. The effect of different electro-explosion voltages on hydrogen evolution performance was investigated. The material properties were characterized using FE-SEM, TGA, and BET. Electrochemical properties were assessed using CV, LSV, and CA. FE-SEM analysis revealed that the amount of nickel particles on the foam increased with higher concentrations, with particle sizes ranging from 50 to 300 nm. The sample with 0.15 wt% nickel exhibited lower overpotentials at current densities of -10 mA/cm² and -20 mA/cm², measuring 204.2 mV and 280.1 mV, respectively.
F:P09 Development of Ultraporous Activated Carbons derived by FDM PEI Wastes: The ECOSTORE H2 Project
A. ZOTTI1, L. SIMEONE2, T. PADUANO1, S. ZUPPOLINI1, M. ZARRELLI1, V. VENDITTO2, A. BORRIELLO1, 1CNR-IPCB, Portici (NA), Italy; 2Università degli studi di Salerno, Salerno, Italy
In recent years, the development of additive manufacturing technologies has made significant progress, leading to printing of technopolymers with properties comparable to those of commonly used metal alloys. However, during complex geometries printings (such as turbine blades, pipes, etc.), considerable amounts of waste are generated (supports or discarded parts), which require proper disposal. Polyetherimide (PEI) is a technopolymer commonly used in FDM processes, characterized by high mechanical properties and remarkable thermal stability (Tg ~220°C): being employed for the manufacture of complex engineering components, a significant amount of manufacturing waste is produced. One possible approach to recycle those wastes could involve the controlled carbonization of these polymers to produce ultraporous activated carbons (UAC), used in many applicative fields such as pollutant adsorbents in water or air (VOCs) as well as energy (batteries and capacitors) and hydrogen storage. In the present work preliminary results on production of UAC derived from PEI wastes, chemically activated using KOH, and their characterization in terms of porosimetry and VOC adsorption capacity are reported.
F:P10 Recycling Expired Thermosetting Resins by the Production of Ultraporous Carbons: The ECOSTORE-H2 Project
S. ZUPPOLINI, A. ZOTTI, T. PADUANO, M. ZARRELLI, A. BORRIELLO, IPCB-CNR, Portici (NA), Italy; V. VENDITTO, L. SIMEONE, UNISA, Fisciano (SA), Italy; V. VINTI, AVIO S.p.A., Colleferro (RM), Italy
Thermosetting resins are a class of polymers characterized by an irreversible transition (crosslinking) from a viscous liquid state to a solid one, featuring excellent mechanical properties and good thermal and chemical stability. For these reasons, thermosetting resins are widely used in numerous sectors, including coatings, adhesives, electronics and aerospace, with an annual global production in 2022 of approximately 6.2 million tons. However, thermosetting resins are characterized by a shelf life, beyond which the polymer can no longer be used since its original properties are no longer guaranteed. Consequently, the need to dispose of large quantities produced annually is a serious problem. An interesting approach for their recycling could be the production of ultraporous activated carbons (UAC), which are suitable materials to be used in many applicative fields such as pollutant adsorbents in water or air (VOCs) as well as energy (batteries and capacitors) and hydrogen storage. In the present work, an expired epoxy resin was used for production of UAC by a chemical activation process, employing different concentrations of KOH (activating agent) to study its effect on the porosity of the obtained system. Preliminary VOC adsorption tests were carried out on the produced carbon.
F:P11 Hydrogen Absorption and Structure of Rapidly Quenched TiZr-based Aperiodic Alloys at Extreme Conditions
JAEYONG KIM, Department of Physics, Hanyang University, Seoul, Korea
TiZrNi alloys exhibit rich structural phases including quasicrystals, approximants, large unit cell crystalline (a~13 Å), in addition to the conventional crystals and metallic glasses, depending on their cooling rates from liquids. Because of the abundant interstitial sites formed with hydrogen favorable Ti and Zr atoms, quasicrystals are known to store significant amount of hydrogen. Here, we report the record-high hydrogen loading capacity in quasicrystals including Al-based ones. Synchrotron based X-ray diffraction data revealed that Ti53Zr27Ni20 quasicrystals absorb 3.4 wt. % of hydrogen at 5.08 GPa of hydrogen pressure without a phase transformation. No impurity phase or significant peak broadening was found. The quasicrystal structure was maintained up to 30 GPa with a saturation of the hydrogen content. Approximately half of the absorbed hydrogen atoms were recycled, which demonstrates that TiZrNi quasicrystals can be used for a practical use of hydrogen storage applications. Such the high hydrogen loading capacity is the unique property of Ti-based quasicrystals. The dynamics and stability of structure at high pressure will also be presented.
F:P12 Alkaline Earth Metal Oxide-Promoted Ni–YSZ Anodes for Ammonia Solid Oxide Fuel Cells (SOFCs)
S. LEE, H.-M. CHO, K. KIM, HAEJIN HWANG, Dep. of Mater. Sci. & Eng., Inha University, Incheon, Republic of Korea
Ammonia is a carbon-free fuel that thermally decomposes to H₂ and N₂ under catalytic conditions. Nickel is an effective, low-cost catalyst for this reaction, enabling ammonia-fueled solid oxide fuel cells (SOFCs) to internally crack NH₃ and utilize the generated H₂. However, Ni activity declines at intermediate temperatures (~650 °C), limiting overall cell performance. Here, we enhance the catalytic function of Ni–YSZ anodes by infiltrating alkaline-earth metal (AEM) species—barium (Ba), strontium (Sr), calcium (Ca), and magnesium (Mg). Button-type SOFC single cells with Ni–YSZ-supported anodes were evaluated under NH₃ fuel. Open-circuit NH₃-cracking tests, polarization (I–V), and electrochemical impedance spectroscopy (EIS) quantified catalytic and electrochemical improvements, and durability was assessed over 100 h. Among the modified electrodes, Ba-infiltrated Ni–YSZ showed the largest performance gain and superior stability. Post-test SEM/EDS revealed a well-dispersed AEM phase at the Ni/YSZ interface without detrimental coarsening. Computational analysis shows that alkali(-like) promoter effects at the Ni surface—realized here via alkaline earth metal oxide decoration—donate electron density to Ni, shifting the Ni d-band center and lowering the work function.
F:P13 Enhanced CO₂ Electroreduction Performance Using Mixed-Valence Cu Catalysts and NiFeOx Anodes in a Membrane Electrode Assembly
S. CAMPAGNA ZIGNANI, A. CARBONE, A.S. ARICÒ, Institute of Advanced Energy Technologies (ITAE) of the Italian National Research Council (CNR), Messina, Italy
The continuous rise in atmospheric CO₂ emissions poses a major environmental threat requiring urgent solutions. Among mitigation strategies, electrochemical CO₂ reduction (CO₂RR) offers a promising route by converting CO₂ and water into green fuels, reducing emissions and storing renewable energy. Product distribution in CO₂RR strongly depends on the electrocatalyst. Copper (Cu), widely studied under alkaline conditions, can produce over 30 products, including hydrocarbons and alcohols, but suffers from poor selectivity. Enhanced performance can be achieved by engineering the catalyst surface to increase active site density. Using the oxalation method, Cu structures with oxidation states from 0 to +2 were obtained, improving catalytic activity. A NiFeOx-based anode was synthesized via co-precipitation. A membrane electrode assembly (MEA) was formed by cold-pressing both electrodes with an anion exchange membrane. Electrodes were prepared by spray-coating catalytic inks onto Sigracet GDL (cathode) and Bekaert Ni felt (anode). Tests in a zero-gap cell at 300 mA cm⁻² under alkaline conditions showed CO₂RR products including H₂, CO, C₂H₄, ethanol, and propanol, consistent with reported intermediates and pathways.
F:P14 Non-Precious Catalysts and Commercial Anion Exchange Membranes for Cost-Effective AEM Water Electrolysis
C. LO VECCHIO, G. BUCCA, M. AHMED, A. PATTI, M.G. BOTTARI, I. GATTO, V. BAGLIO, Consiglio Nazionale delle Ricerche, Istituto di Tecnologie Avanzate per l’Energia “Nicola Giordano”, CNR-ITAE, Messina, Italy
This work presents membrane electrode assemblies (MEAs) for anion exchange membrane water electrolysis (AEMWE) using mixed transition-metal oxide anodes and commercial anion exchange membranes (AEMs). MEAs were tested in a lab AEM electrolyzer and benchmarked against systems with commercial membranes and PGM catalysts. Non-PGM catalysts showed competitive results, with Ni–Fe oxides delivering high OER activity due to synergistic effects and improved charge-transfer kinetics. The new AEMs provided high hydroxide conductivity and mechanical stability in alkaline media, enhancing efficiency and durability. Combining earth-abundant catalysts with robust membranes is a promising route to lower costs while maintaining performance. Further optimization of materials and MEA design can enable scalable, sustainable hydrogen production and accelerate AEMWE industrial deployment.
This work was supported by MAECI within the Italian-German initiative “Green Hydrogen Research” under the DURALYS project on durable and scalable AEMWE components.
F:P15 Local Structure Analysis of High Proton Conductors by Solid-State NMR
M. TANSHO, National Institute for Materials Science (NIMS), Tsukuba, Japan
In recent years, it has been reported that hydrated cubic perovskite-type barium scandate-based materials exhibit high proton conductivity, with conductivities exceeding 0.01 S cm⁻¹ at temperatures above 320°C. According to ab initio molecular dynamics (AIMD) simulations, the reason for the high proton diffusion coefficient D is that protons are not found near oxide ions coordinated to dopant cations. Instead, due to the repulsion between the donor and H+, protons are present near oxide ions coordinated to Sc³⁺ cations. In this study, to investigate the effects of oxygen vacancies and hydration, the local structure of as-prepared samples presumed to be insufficiently hydrated was analyzed using solid-state nuclear magnetic resonance (NMR).
F:P17 Enhanced High-Temperature Stability and Performance of LiFePO4 Cathodes via LiPF6-Derived Secondary Coating
JI WON CHO, YONG JOON PARK, Department of Advanced Materials Engineering, Kyonggi, Gyeonggi-do, Republic of Korea
Lithium-ion batteries (LIBs) are essential for electric vehicles, wearable devices, and energy storage systems owing to their high energy density and reliability. Among cathodes, lithium iron phosphate (LiFePO₄, LFP) offers high structural stability, long cycle life, and low cost. However, its low electronic conductivity and slow lithium-ion diffusion limit rate capability. Although carbon coating is widely used to mitigate these issues, the carbon layer can react with the electrolyte during cycling or at high temperatures, leading to interfacial degradation. In this study, a secondary LiF coating was introduced via controlled decomposition of LiPF₆ to enhance interfacial stability of LFP. LiPF₆ decomposes thermally or by hydrolysis to form LiF and PF₅, and LiF forms a uniform, tightly bound protective layer on the LFP/C surface. This fluoride layer suppresses electrolyte decomposition and metal dissolution, improving electrochemical and thermal stability. The LiF coating was obtained through a simple, scalable solution process with strong adhesion to the carbon layer. Consequently, the modified LFP exhibited enhanced capacity retention and interfacial stability during high-temperature cycling, offering a cost-effective strategy for durable, high-performance LFP cathodes.
F:P18 Interface Stabilization Between Cathode and Sulfide Electrolyte Through Vapor-Phase Phosphorus Surface Modification
EUN CHAN HEO, YONG JOON PARK, Department of Advanced Materials Engineering, Kyonggi, Gyeonggi-do, Republic of Korea
Lithium-ion batteries are widely used in devices from portable electronics to electric vehicles (EVs) and energy storage systems (ESSs) due to their high energy density and low weight. However, the flammability of organic electrolytes raises safety issues, driving interest in all-solid-state batteries (ASSBs) with inorganic solid electrolytes. Among them, sulfide-based electrolytes are promising for practical use because of their high ionic conductivity and favorable mechanical properties, but interfacial degradation with oxide cathodes remains a major challenge. Conventional oxide coatings from solution processes have been studied to mitigate this, yet their high cost and complex solvent handling limit scalability. Here, we propose a simple and low-cost vapor-phase modification using an inexpensive precursor to suppress side reactions at the cathode–electrolyte interface. This method forms a byproduct-like interfacial layer in situ, passivating the interface effectively. Phosphorus pentoxide (P₂O₅), which sublimates at low temperatures, creates a thin uniform protective layer through one-step heat treatment, avoiding costly ALD or CVD. This solvent-free and scalable process provides a practical route for interfacial stabilization in sulfide-based ASSBs.
F:P19 Strategy to Enhance Electrochemical Performance of LMFP Cathodes via Cation Co-doping
SEOK IN LEE, YONG JOON PARK, Department of Advanced Materials Engineering, Kyonggi, Gyeonggi-do, Republic of Korea
Lithium-ion batteries are widely used in electric vehicles, wearable devices, and energy-storage systems. Lithium manganese iron phosphate (LMFP) is attractive for its thermal stability, robust raw-material supply, cost-effectiveness, and higher operating voltage than LiFePO₄. However, practical use is limited by low electronic conductivity, sluggish Li-ion diffusion, and Mn-centered Jahn–Teller distortion, which depress rate performance and durability. Surface coating and cation doping have been explored extensively, yet scalable and more effective solutions are still needed. This work presents a cost-effective LMFP route using inexpensive source materials combined with cation co-doping by V, Ti, and Mg. Aqueous precursors are spray-dried into secondary particles and heat-treated under inert gas. Co-doping stabilizes the olivine lattice, suppresses antisite defects impeding Li transport, and mitigates Jahn–Teller activity by reinforcing local MO₆ octahedra, thereby improving charge transport. Relative to undoped LMFP, the co-doped material delivers higher capacity retention, enhanced high-rate capability, and more stable voltage behavior. These results define a practical, material-efficient design for LMFP cathodes aligned with EV/ESS performance and manufacturability demands.
F:P20 Assessing the Viability of Zr-, Fe-, and Mn-fumaric Acid Metal Organic Frameworks as Conductive Agents through Solid Hydroxyethyl Cellulose Polymer Electrolytes
F. MICHEAL, S. ROHANA MAJID, S.N. ABDUL HALIM, Universiti Malaya, Kuala Lumpur, Malaysia
The search for safer and greener alternatives to conventional liquid electrolytes has prompted continuous research in the development of flexible biopolymer-based solid electrolytes, though the low electrical conductivity of biopolymers poses a challenge. In this study, metal-organic frameworks (MOFs) were studied as potential enhancers, in which a series of MOFs (Zr-, Fe-, and Mn-based) using a simple linker, fumaric acid, were synthesized and their chemical and physical properties were characterized by using FTIR, FESEM, PXRD, and TGA. Subsequently, these MOFs were blended with hydroxyethyl cellulose (HEC), alongside ammonium thiocyanate as cation provider, to form HEC-MOF(Zr), HEC-MOF(Fe), and HEC-MOF(Mn) composite materials. Electrochemical impedance spectroscopy reveals that, for all three types of MOF, the addition of MOF at 0.025 g per 0.4 g HEC raises the conductivity of HEC-salt blend to more than (3 ± 2) × 10-4 S cm-1. In addition, linear sweep voltammetry indicates all three types of MOF-doped composite materials possess electrochemical stability window comparable to undoped HEC-salt blend at 2.00 V. Galvanostatic charge-discharge analysis shows that HEC-MOF(Mn) film, with 0.050 g MOF per 0.4 g HEC, exhibits the best average specific capacitance at 140 ± 10 F g-1.
F:P21 Lightweight UHPC with Integrated Structural Insulation: Towards a Low-carbon Building
ZUSHI TIAN, HAILONG YE, Department of Civil Engineering, The University of Hong Kong, Hong Kong
Modular integrated construction (MiC) is transforming the construction industry by enhancing productivity, safety, and sustainability. This study delved into the potential of incorporating artificial lightweight aggregates made from recycled glass into the production of lightweight, high-strength, low-carbon, and thermally insulating structural concrete, i.e., lightweight ultra-high-performance concrete (UHPC) and lightweight C60 concrete. Their impact on the total carbon emissions of MiC high-rise residential buildings was investigated. In this work, the integrated analysis of material-structure-building interactions was emphasized. The results indicate that, for lightweight UHPC, the increased unit volume carbon emissions could be offset by its extended service life and reduced concrete consumption, resulting in slightly lower embodied carbon emissions compared to traditional C60 concrete. The integrated analysis revealed that the use of lightweight C60 concrete could reduce total carbon emissions by 5.4%, while lightweight UHPC could achieve a 6.2% reduction due to its longer building lifespan and superior insulation properties.
F:P22 Tissue Engineering Based on Freestanding Hydroxyapatite Membranes
HIROAKI NISHIKAWA, B.O.S.T. Kindai University, Kinokawa, Japan
Tissue engineering has been quite developed by a cell membrane engineering using temperature responsive polymer, e.g., poly (N-isopropylacrylamide) as a scaffold. However, it is difficult to construct 3-dimensional cell membranes by this technique because the cell membrane is detached from the scaffold before it is transplanted into body. The cell membrane will not keep complicated shape after detachment. For the problem, we have noted a hydroxyapatite (HA) as a suitable scaffold material. HA has excellent biocompatibility, so cell membrane can be transplanted with the HA scaffold which can keep the designed shape. In this study, we report the development of the HA membranes with various shapes and its application to scaffold for the cell membrane engineering. HA was deposited on NaCl substrate of plate, rod and hemisphere shapes by pulsed laser deposition, then the sample was immersed in purified water to dissolve the NaCl substrate. The HA membrane was annealed to crystallize the HA. We have examined in-vitro cultivation of immortalized stromal cell line (KUSA-A1) established from murine bone marrow cultures on HA membranes. KUSA-A1 cell membrane cultivated on HA membrane shows that the HA membrane is effective for the scaffold of the cell membrane.
F:P23 Visco-pseudo-elastic Modelling of Elastomeric Membranes subject to bi-axial Stretching
A. JALALIAN, G. ROSATI PAPINI, G. RIZZELLO, G. MORETTI, University of Trento, Italy; Saarland University, Germany
A thermodynamically consistent visco–pseudo–elastic constitutive model is proposed for elastomeric membranes undergoing finite deformations, with particular relevance to dielectric elastomer actuators (DEAs). The formulation relies on a rheological description of the material, which combines a hyperelastic equilibrium response with viscoelastic and rate-independent dissipative contributions, represented through internal stretch variables within a nonequilibrium thermodynamic framework. The model holds for biaxial membrane stretch states, without a-priori assumptions on the deformation kinematics, and it is validated against experiments on a styrene-based rubber subject to large stretches (>2.5). Material parameters are identified from pure-shear experiments using a nonlinear least-square approach, where internal variables evolve along prescribed stretch histories. The identified parameters are validated against independent datasets and further used to predict the response under complex biaxial deformations. Results show that parameters identified from simple monoaxial tests can capture complex multiaxial behaviors, including hysteresis and rate-dependent effects. The proposed framework provides a predictive tool for the modeling and design of DEA-based devices.
F:P24 Impact of Double Doping on the Thermoelectric Performance of Permingeatite
SONG SEOK, HYEON-SIK O, YURIM LEE, BONG-KI HONG, HO-JEONG KIM, HEE-JAE AHN, SANG JUN PARK, IL-HO KIM, Core-Facility Center for Thermoelectrics, Korea National University of Transportation, Chungju, Republic of Korea
Ternary Cu–Sb–Se chalcogenides are abundant, non-toxic, and promising as environmentally friendly semiconductors. Permingeatite (Cu₃SbSe₄) has a high Seebeck coefficient and low lattice thermal conductivity, but low intrinsic carrier concentration limits ZT. This study applied dual doping by substituting Sb with Sn/Bi, Sn/In, and Ge/In, or co-doping Sb/Se with Sn/S and Ge/S, to improve thermoelectric performance. Cu₃Sb₀.₉₂Sn₀.₀₆Bi₀.₀₂Se₄ achieved the highest ZT of 0.75 at 623 K. Cu₃Sb₀.₉₂Sn₀.₀₄In₀.₀₄Se₄ and Cu₃Sb₀.₉₈Sn₀.₀₂Se₃.₅₀S₀.₅₀ reached ZT of 0.59 and 0.68, demonstrating effective Sb-site and Sb/Se co-doping. Ge-doped samples had ZT of 0.47 and 0.37, showing that Ge can tune carrier concentration and thermal conductivity. Dual doping balances carrier concentration and lattice thermal conductivity, with Sn/Bi substitution at Sb being the most effective strategy to enhance thermoelectric performance.
This study was supported by the Small-Medium Enterprise Innovation Growth Support Project of the Korea RIC Association and the Basic Science Research Capacity Enhancement Project (National Research Facilities and Equipment Center) through the Korea Basic Science Institute funded by the Ministry of Education (Grant No. 2019R1A6C1010047).
F:P25 Investigation of n-Type Behavior in Zn-Doped Chalcopyrite for Thermoelectric Applications
SOO-SUN LEE, JIN-SOL KIM, IL-HO KIM, Core-Facility Center for Thermoelectrics, Korea National University of Transportation, Chungju, Republic of Korea
The effect of Zn doping on the n-type thermoelectric properties of chalcopyrite (CuFeS₂) was investigated. Cu₁₋ₓZnₓFeS₂ (x = 0.02–0.08), with Zn²⁺ substituting Cu⁺, was synthesized via mechanical alloying and hot pressing. X-ray diffraction showed that Zn doping did not significantly alter the chalcopyrite structure, and all samples remained single-phase, indicating minimal lattice distortion. Electrical conductivity increased with Zn content, while the Seebeck coefficient decreased due to higher electron carrier concentration. Thermal conductivity showed little change, limiting improvements in the power factor and figure of merit. Overall, Zn doping enhanced n-type electrical conductivity but had only a modest effect on thermoelectric performance, suggesting that further optimization is needed to significantly improve ZT in chalcopyrite.
This study was supported by the Small-Medium Enterprise Innovation Growth Support Project of the Korea RIC Association and the Basic Science Research Capacity Enhancement Project (National Research Facilities and Equipment Center) through the Korea Basic Science Institute funded by the Ministry of Education (Grant No. 2019R1A6C1010047).
F:P26 Effect of Zn Doping on the Thermoelectric Performance of Eskebornite
JONG-KI WON, SE-HYEON CHOI, IL-HO KIM, Core-Facility Center for Thermoelectrics, Korea National University of Transportation, Chungju, Republic of Korea
Eskebornite (CuFeSe₂) is a I–III–VI₂ ternary semiconductor with properties distinct from the structurally similar chalcopyrite (CuFeS₂). Undoped CuFeSe₂ was obtained as a single phase with high relative densities of 99.1%–99.6% and exhibited non-degenerate semiconducting behavior, showing increasing electrical conductivity with temperature. At 523 K, it achieved a power factor of 1.52 μW m⁻¹ K⁻² and thermal conductivity of 2.11 W m⁻¹ K⁻¹, resulting in a maximum ZT of 0.37 × 10⁻³. Zn-doped Cu₁₋ₓZnₓFeSe₂ (x = 0.02–0.08) samples were synthesized via mechanical alloying and hot pressing. Doping maintained p-type conduction, and the Cu₀.₉₈Zn₀.₀₂FeSe₂ sample showed the highest power factor of 1.12 μW m⁻¹ K⁻² at 423 K and a maximum ZT of 0.25 × 10⁻³ at 473 K, demonstrating that Zn substitution cannot effectively modulate the thermoelectric performance of eskebornite. Acknowledgments: This study was supported by the Small-Medium Enterprise Innovation Growth Support Project of the Korea RIC Association and the Basic Science Research Capacity Enhancement Project (National Research Facilities and Equipment Center) through the Korea Basic Science Institute funded by the Ministry of Education (Grant No. 2019R1A6C1010047).
F:P27 Thermoelectric Properties of Te-Doped Permingeatite Prepared via Solid-State Synthesis
DONG-KIL SHIN, MIN-CHUL KWON, IL-HO KIM, Core-Facility Center for Thermoelectrics, Korea National University of Transportation, Chungju, Republic of Korea
Te-doped Cu₃SbSe₄₋ᵧTeᵧ (y = 0.02–0.08) compounds were synthesized via mechanical alloying and hot pressing, yielding dense permingeatite -phase compacts with relative densities above 96.4%. The Seebeck coefficient increased with temperature up to 473 K and then decreased, with higher Te content reducing its value; the maximum of 349 μV K⁻¹ was observed at 473 K for y = 0.04. Electrical conductivity decreased with both increasing temperature and Te content, reaching 4.2 × 10³ S m⁻¹ at 623 K for y = 0.02. The power factor was maximized at 0.42 mW m⁻¹ K⁻² at 623 K for Cu₃SbSe₃.₉₈Te₀.₀₂ due to the combination of high Seebeck coefficient and conductivity. All samples exhibited low thermal conductivities below 1.2 W m⁻¹ K⁻¹, attributed to suppressed electronic thermal transport. Consequently, Cu₃SbSe₃.₉₈Te₀.₀₂ achieved the highest ZT of 0.34 at 623 K, demonstrating the effectiveness of Te doping in optimizing thermoelectric performance.
This study was supported by the Small-Medium Enterprise Innovation Growth Support Project of the Korea RIC Association and the Basic Science Research Capacity Enhancement Project (National Research Facilities and Equipment Center) through the Korea Basic Science Institute funded by the Ministry of Education (Grant No. 2019R1A6C1010047).
F:P28 Enhanced Thermoelectric Properties of Tetrahedrite via Site-Specific Doping
JOON-CHUL KWON, SUNG-GYU KWAK, IL-HO KIM, Core-Facility Center for Thermoelectrics, Korea National University of Transportation, Chungju, Republic of Korea
The effects of site-specific doping on the thermoelectric properties of tetrahedrite (Cu₁₂Sb₄S₁₃) were investigated by substituting Cu with Zn, Sb with Bi or Te, and S with Se. Doped samples were synthesized by mechanical alloying at 350 rpm for 24 h under Ar and consolidated by hot pressing at 723 K for 2 h under 70 MPa, yielding dense compacts with relative densities above 98%. Doping effectively tuned the carrier concentration, which controlled the Seebeck coefficient and electrical conductivity, thereby optimizing the power factor and reducing thermal conductivity. As a result, thermoelectric performance was significantly enhanced. The maximum ZT values reached 0.76 for Cu₁₁.₆Zn₀.₄Sb₄S₁₃, 0.88 for Cu₁₂Sb₃.₉Bi₀.₁S₁₃, 0.80 for Cu₁₂Sb₃.₉Te₀.₁S₁₃, and 0.87 for Cu₁₂Sb₄S₁₂.₈Se₀.₂ at 723 K, demonstrating that site-specific doping is an effective strategy for enhancing the thermoelectric performance of tetrahedrite.
This study was supported by the Small-Medium Enterprise Innovation Growth Support Project of the Korea RIC Association and the Basic Science Research Capacity Enhancement Project (National Research Facilities and Equipment Center) through the Korea Basic Science Institute funded by the Ministry of Education (Grant No. 2019R1A6C1010047).
F:P29 Preparation and Thermoelectric Performance of Non-Stoichiometric Skinnerite
SANG JUN PARK, IL-HO KIM, Core-Facility Center for Thermoelectrics, Korea National University of Transportation, Chungju, Republic of Korea
Non-stoichiometric skinnerite (Cu₃₊ₘSbS₃) was synthesized by mechanical alloying and hot pressing to examine the impact of Cu deficiency and excess on phase formation and thermoelectric properties. XRD confirmed cubic skinnerite, while Cu-rich samples contained a secondary tetrahedrite phase. DSC revealed a single melting peak at 876 K for stoichiometric skinnerite, whereas non-stoichiometric samples showed additional transitions at 814–818 K and melting near 874 K. Electrical conductivity increased with temperature, indicating non-degenerate semiconducting behavior. All non-stoichiometric samples exhibited higher conductivity above 423 K. A positive Seebeck coefficient confirmed p-type conduction; Cu deficiency lowered the Seebeck coefficient but enhanced the power factor. Cu₂.₉₈SbS₃ achieved the highest power factor (0.85 mWm⁻¹K⁻²) and a peak ZT of 0.59 at 623 K, outperforming stoichiometric Cu₃SbS₃ (ZT = 0.51).
This study was supported by the Small-Medium Enterprise Innovation Growth Support Project of the Korea RIC Association and the Basic Science Research Capacity Enhancement Project (National Research Facilities and Equipment Center) through the Korea Basic Science Institute funded by the Ministry of Education (Grant No. 2019R1A6C1010047).
F:P30 Experimental and Numerical Investigation of Thermal Fatigue in Solder Joints for Thermoelectric Devices
SEUNGWOO HAN1,2, SEUNGIK SHIN2, SEONG-JAE JEON1, JUNG YUP KIM1, 1Department of Nano-devices and displays, Korea Institute of Machinery and Materials, Daejeon, South Korea; 2Department of Nanomechatronics, University of Science and Technology, Daejeon, Republic of Korea
Thermoelectric devices undergo cyclic heating and cooling during operation, causing thermal fatigue in solder joints that limits reliability. To assess intrinsic fatigue behavior under realistic conditions, we developed a Peltier-effect-based test system, where alternating current through the thermoelectric element generates thermal cycles without external heaters or coolers. Commercial modules were cut to isolate single joints, and resistance was monitored during cycling until failure, defined as a 20% increase in resistance. Fatigue life showed strong dependence on the applied thermal gradient. Complementary finite element analysis with coupled thermo-electric–mechanical physics and the Anand viscoplastic model quantified solder deformation and energy dissipation. Correlating simulations with experimental lifetimes enabled application of the Darveaux model to establish an inelastic strain-energy density–life relationship. Both experiments and simulations revealed clear asymmetry: n-type joints consistently outlasted p-type. These findings highlight the intrinsic reliability difference in thermoelectric devices and provide guidance for predictive design in cooling, energy harvesting, and aerospace systems.
F:P31 Ribbon-shaped Mn49(Ni39Fe4)Sn8 Metamagnetic Shape Memory Alloys: Solidification Rate Influence on the Observed Structural, Magnetic and Magnetocaloric Properties
J. GUTIÉRREZ, N.A. RÍO-LÓPEZ, M. RÍOS, D. MÉRIDA, P. LÁZPITA, EHU, Faculty of Science and Technology, Leioa, Spain; D. SALAZAR, BCMaterials, Basque Center for Materials, Applications and Nanostructures, EHU Science Park, Leioa, Spain
The martensitic transition in Mn-rich, Mn-Ni-X (X=In, Sn, Sb) Heusler-type alloys from a low magnetization martensite to a high magnetization austenite reflects in a large magnetization difference ΔM across the transformation, the associated magnetic entropy change (ΔSM) and a temperature change of the material that gives rise to the well-known magnetocaloric effect (MCE). Previously, we investigated Mn (excess)-Ni-Sn doped with Fe alloys concluding that the Fe addition up to 4 % reduces the martensitic transformation hysteresis accompanied by an increase in ΔM [1]. So, now we have fabricated melt spun ribbons (with a large surface-to-volume ratio that favor heat exchange) of the optimal composition Mn49(Ni39Fe4)Sn8 to study the effect of the ribbon solidification rate on the structure, microstructure, martensitic transformation and magnetic properties, as well as on functional properties. Melt-spun samples were fabricated at wheel speeds from 10 m/s to 30 m/s. With increasing cooling rate, grain size and ribbon thickness decrease, while the martensitic and magnetic transformation temperatures, as well as the Curie temperature, increase. Moreover, the sample fabricated at 15 m/s shows the maximum value of ΔM =25 Am2/kg.
[1] Lázpita, P. et al., (2018) Scripta Materialia, 155, 95
F:P32 Reversible Temperature Change With Low Hysteresis in Ni-Mn-In-Co-Cu Alloys
P. LA ROCA, Centro Atómico Bariloche (CNEA), CONICET, Bariloche, Argentina; J. LÓPEZ-GARCÍA, Department of Physics, Faculty of Science, University of Oviedo, Oviedo, Spain; V. SÁNCHEZ-ALARCOS, A. URBINA, V. RECARTE, J.I. PÉREZ-LANDAZÁBAL, Dept. Science & Institute for Advanced Materials and Mathematics (INAMAT2), Universidad Pública de Navarra, Pamplona, Spain
Solid-state refrigeration have emerged as a highly promising, eco-friendly, and more efficient alternative to traditional gas compression systems in cooling applications [1]. In particular, NiMn-based Heusler alloys, are promising candidates since they do not contain precious, expensive, toxic or rare-earth elements and shows giant magnetocaloric effect. Unfortunately, the large thermal hysteresis typically observed in Heusler alloys, has a negative impact on cyclical operations due to degradation, increase of the hysteresis losses and decrease of the reversibility and efficiency [2]. The reduction of thermal hysteresis and the improvement of the cycling reversibility of magnetocaloric materials are the main challenges to be face against commercial viability of magnetic refrigeration devices. The present work is focused on the characterization of the reversibility of the martensitic transformation where the results shows that the reversibility strongly depends on the applied magnetic field. A phenomenological model was proposed to estimate a theoretical field dependence upper limit of the reversibility. This approach matches the experimental results satisfactorily and contributes to understand and quantify the relation between magnetic field, hysteresis and the reversibility.
F:P33 Coiled CNT@Nylon Hybrid Fibers for Bias Voltage Free Self-Sensing Thermo Actuation
HOCHEOL GWAC, JAE SANG HYEON, SEON JEONG KIM, Department of Biomedical Engineering and Electronic Engineering, Hanyang University, Seoul, Republic of Korea
Fiber shaped artificial muscles offer lightweight, flexible actuation, yet most systems prioritize motion alone and lack built-in monitoring. Here we present a thermo-driven, coiled CNT@nylon hybrid fiber that integrates actuation and self-sensing at the material level. A nylon core provides reversible thermal contraction, while a carbon nanotube sheath transduces deformation into an open-circuit voltage, enabling real-time monitoring of muscle state without external power. This approach simplifies wiring, improves spatial efficiency, and yields an intrinsic signal readily usable for closed-loop operation. Inspired by arrector pili–mediated thermoregulation, we outline an application concept for adaptive ventilation and environmental response. This multifunctional platform advances compact, compliant, self-powered artificial muscles for soft robotics, wearable systems, and biointegrated electronics.
F:P34 Piezoelectrochemical Energy Harvesting from Carbon Nanotube Yarn with Polymer Coating
GYU HYEON SONG, JAE SANG HYEON, SEON JEONG KIM, Department of Biomedical Engineering and Electronic Engineering, Hanyang University, Seoul, Republic of Korea
The rapid development of the Internet of Things (IoT) has increased the demand for electronic devices, thereby driving research into mechanical energy harvesters that utilize human motion as a power source. Among these, piezoelectrochemical energy harvesters are particularly promising for wearable applications due to their high energy densities at low frequency motion. However, practical use of piezoelectrochemical harvesters requires a two-electrode configuration, in which voltages generated by each electrode often cancel each other, limiting performance. Here, we propose a straightforward strategy to reverse the voltage generation direction of each electrode. By coating carbon nanotubes (CNTs) with positively charged (Vinylbenzyl)trimethylammonium chloride (VBTMA) or negatively charged poly(sodium-4-styrenesulfonate) (PSS), the potential of zero charge (PZC) is shifted in negative and positive directions, respectively. The intrinsic bias voltage which defined as the difference between the open-circuit potential and PZC governs the voltage polarity, with VBTMA@CNT generating positive voltages and PSS@CNT generating negative voltages. These electrodes can be woven into textiles, enabling simultaneous energy harvesting and body motion sensing.
F:P35 Tailored Counterion Coordination for Enhanced Stability and Performance of Rhodamine Color Filters in Nanophosphor Micro-LED Displays
JEE YOUNG LIM, WOOSUNG LEE, Korea Institute of Industrial Technology, Ansan, Korea
Among various candidates, nanophosphor-based micro-LED displays provide exceptional emission efficiency across wide spectral regions. Nevertheless, their full potential relies on color filters that selectively manage light transmission with high precision. Rhodamine derivatives exhibit sharp and strong absorption properties as red colorants for color filters, but they are prone to thermal and photodegradation. In this work, we synthesized a rhodamine derivative by introducing a weakly coordinating anion to enhance both its optical performance and stability. Its absorption properties, heat/light stability, and solubility in industrial solvents were examined to evaluate the dye for color filter applications. The synthesized dye showed superior optical properties and exhibited improved stability and solubility due to the introduced counteranion. Additionally, a color filter was prepared based on the synthesized dye, and its characteristics were investigated. This work offers a practical and scalable approach for producing durable, high-performance color filters based on counterion-coordinated rhodamine dyes, advancing next-generation nanophosphor micro-LED display technologies.
F:P36 Photoluminescence of Freestanding Films using Pr-doped CaSrTiO3 Nanoparticles Prepared by Supercritical Hydrothermal Synthesis
HIROSHI TAKASHIMA, KIWAMU SUE, AIST, Tsukuba, Ibaraki, Japan
Perovskite oxides have been extensively studied for many years due to their excellent chemical stability and simple structure. Recently, low-voltage driving electroluminescence (EL) has been realized in thin-film multilayer structures. To achieve EL conveniently, we developed a paste using phosphor nanoparticles and fabricated freestanding films via a simple screen printing method. Pr-doped CaSrTiO3 perovskite nanoparticles were synthesized by continuous supercritical hydrothermal method (2), with an average particle size of 11 nm. TEM observation confirmed a distinct lattice pattern, verifying its single-crystal-like structure. The luminescence of the obtained film and the sintered freestanding film were investigated, revealing strong emission corresponding to a wavelength of 612 nm. This is attributed to the energy transition from 1D2 to 3H4 of the Pr³⁺ ion, identified as high-purity red luminescence. Screen printing enables selective control of films ranging from approximately ten micrometers to several hundred micrometers thick. Therefore, the development of freestanding phosphor films using nanoparticles as materials is expected to significantly contribute to the advancement of electroluminescent device development.
F:P37 Energy Transfer and Site-Dependent Luminescence in Eu3+-Ti4+ Codoped Sr-Based Perovskite-Type Oxides
KAZUSHIGE UEDA, KEIGO NAKAMURA, Kyushu Institute of Technology, Kitakyushu, Japan
It is well known that Eu3+ shows different photoluminescence features between at A and B sites in Sr-based simple perovskite-type oxides (ABO3), such as SrZrO3 and SrSnO3. On the other hand, Ti4+-doped Sr-based layered perovskite-type oxides, Sr2SnO4:Ti4+, have been reported to show blue luminescence and give red luminescence also by Eu3+ codoping due to the energy transfer from Ti4+ to Eu3+. These facts imply that the energy transfer from Ti4+ to Eu3+ may occur not only in the layered perovskite-type oxides but also in the simple perovskite-type oxides. Therefore, in this study, the energy transfer and site-dependent luminescence properties were examined in the Eu3+-Ti4+ codoped simple perovskite-type oxides, where Eu3+ were doped site-selectively at either A or B sites. The results revealed that the energy transfer from Ti4+ did not occur equivalently against Eu3+ at A sites and Eu3+ at B sites.
F:P38 Ultrafast THz Detection based on Plasmonic Rectification Implemented with Active Photonic Strcuture in Van Der Waals Semimetals
CHAO TANG, Tohoku University, Sendai, Miyagi, Japan
We present an ultrafast terahertz (THz) detection platform that integrates plasmonic rectification with active photonic architectures in van der Waals (VDW) semimetals. An asymmetric dual-grating-gate field-effect transistor (ADGG-FET) based on graphene was developed to generate periodic carrier-density modulation, inducing collective plasmon oscillations that rectify incident THz fields without source-drain bias. The device exhibits a responsivity of 48 mV/W and a response time of 185 ps at room temperature, demonstrating that the plasmonic rectification effect dominates the THz photoresponse. Furthermore, by incorporating optical excitation and dynamic gating, the transition between plasmonic rectification and unipolar photothermoelectric regimes can be controlled, enabling tunable carrier transport and enhanced nonlinear coupling between optical and THz domains. This active hybrid structure bridges nanoplasmonics with semiconductor photonics, offering a pathway toward zero-power, broadband, and high-speed THz sensors. The results reveal a scalable strategy for integrating 2D semimetal devices into next-generation photonic and optoelectronic systems for communication, imaging, and spectroscopic applications.
F:P39 Liquid Crystal-polymer Composite for Light Outcoupling in Organic Light Emitting Displays
YOONSEUK CHOI, SEONGMIN LIM, YUJIN SEONG, Hanbat National University, Daejeon, Republic of Korea
The organic light emitting displays(OLEDs) is now used for various display devices including flexible and transparent applications. However, the efficiency of light emitting devices is just only 20 percent due to various kinds of optical disturbance such as internal reflection and refraction. Thus, developing light outcoupling technique is critical for brighter screen with low power consumption. In this research, we demonstrate the liquid crystal-polymer composite based scattering layer with programmable two-dimensional pattern as the light outcoupling layer of OLEDs. In this method, we can manipulate the scattering layer as we designed to lead the high light extraction results. This method is promising for various kinds of OLED application including flexible devices since the scattering layer can be developed on the flexible layer. This research can play a critical role in advanced display technology with high performances.
F:P40 Development of Dense Flint Glass-Cladded YAG Fiber for Single-mode Transmission
D. Y. JHENG, K. Y. HSU, S.L. HUANG, National Taiwan University, Taipei, Taiwan; Y. W. LEE, National Taipei University of Technology, Taipei, Taiwan
Yttrium aluminum garnet (YAG) is an excellent crystalline host suitable for accepting a variety of rare-earth and transition-metal active ion dopants, including Ce3+, Yb3+, Cr4+, Er3+, Tm3+, and Ho3+, with fluorescence spectra ranging from 0.5 to 3 μm. Single-mode silica fibers with a high surface-area-to-volume ratio have enabled various laser advancements ranging from ultra-low-threshold laser operation to high-power double-clad step-index and micro-structured fiber laser operation. Laser brightness can be further scaled up with a crystalline core, provided that the transverse mode quality is maintained. We report the realization and characterization of lanthanum-dense-flint-glass-clad YAG core fiber with a broad single-mode wavelength range. With precision thermal control using the co-drawing laser-heated pedestal growth method, the glass-clad YAG-core fiber can be engineered to fine-tune the guided fiber modes. Utilizing the unique specifics of the mutual positioning of the dispersion curves of the glass and the YAG core, the cut-off wavelength of the core waveguiding can be tuned from 950 nm to 1380 nm with single-mode operation in the wavelength range from 1.5 μm to 3 μm. The single-mode glass-clad crystalline fibers have high potential for lasers and medical uses in the eye-safe wavelength ranges.
F:P41 Combinatorial E-Nose Design Using Oxide Semiconductor Building Blocks for Tailoring Gas Selectivity
JUNG-HOO SEO, SEONG-YOUNG YOON, SANG-MYEONG LEE, SEONG-YONG JEONG†, Division of Advanced Materials Engineering, Kongju National University, Cheonan, Republic of Korea
Oxide-based semiconductor have attracted considerable attention as promising sensor platform owing to their high response and fast detection. Although considerable efforts have been devoted to enhancing gas selectivity, the gas sensing library is still limited because of simple sensing mechanisms. To address this issue, we propose module-based gas sensors as a new strategy for achieving high selectivity toward various gases. For this, oxide chemiresistor building blocks, including sensing materials (i.e., SnO2 and ZnO hollow spheres) and catalytic materials (i.e., Co3O4, MoO3, and NiO yolk-shell spheres), were synthesized by spray pyrolysis. Gas sensing films were fabricated by uniformly mixing the sensing and catalytic building blocks. The pure SnO2 and ZnO sensors did not show selectivity toward specific gases. Notably, the Co3O4-SnO2, MoO3-SnO2, and NiO-ZnO sensors exhibited high selectivity to benzene (SB/SInter = 3.5 at 350 °C), xylene (SX/SInter = 6.5 at 300 °C), and methylbenzene (ST/SInter = 5.3 at 350 °C), respectively. These results are attributed to the synergistic combination effects between the hollow sensing materials and the yolk-shell catalysts. This module-based design can offer a simple and effective strategy for high-performance electronic noses.
F:P42 An Innovative Ultrasensitive Detection Method for Early-Stage Hemolytic Uremic Syndrome
JAI EUN AN, JINYEONG KIM, KYONG-CHEOL KO, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Republic of Korea
Hemolytic uremic syndrome (HUS) is a severe and potentially life-threatening disease characterized by acute renal failure and is commonly caused by Shiga toxins (Stxs) produced by enterohemorrhagic Escherichia coli (EHEC). Early and accurate detection of Stxs is essential for timely diagnosis and effective treatment to prevent serious complications. In this study, we developed an ultrasensitive graphene-based field-effect transistor (FET) biosensor capable of detecting trace levels of Stxs to improve HUS diagnostics. The sensor exhibited remarkable sensitivity, achieving detection limits at the femtogram level while maintaining high specificity against non-target molecules. Unlike conventional fluorescence-based assays, this sensing platform operates without fluorescent labeling, offering a simpler, cost-effective, and scalable alternative. Laboratory evaluations demonstrated rapid response time, high accuracy, and stable performance under various experimental conditions. Integration of this FET biosensor into diagnostic workflows enables earlier detection of Stxs and supports timely clinical intervention for HUS. These results highlight the potential of this technology for future clinical diagnostics and point-of-care applications.
F:P43 Ultra-compact μGC–MOX Platform for Selective Gas Analysis
SEONG-YOUNG YOON, JUNG-HOO SEO, SANG-MYEONG LEE, SEONG-YONG JEONG, Division of Advanced Materials Engineering, Kongju National University, Cheonan, Republic of Korea
Oxide-based chemiresistors (MOX) have received significant attention because of their high gas response, low cost, easy miniaturization, and rapid detection. However, their poor selectivity is still a major limitation, especially for gas mixture analysis. To address this issue, we developed a micro-gas chromatography (μGC) platform by integrating an OV-215 µ-column with a SnO2 hollow sphere-based sensor. This platform enabled effective separation and detection of gas mixture including methanol, benzene, and toluene, with distinct sequential response peaks and a total retention time of about 430 s. For further optimization, three µGC columns with different polarities and MOX sensors with various morphologies and compositions were systematically evaluated. The platform also showed versatility in separating diverse gas families, including ketones, alkanes, and alcohols. These findings highlight the strong potential of the ultra-compact μGC–MOX platform for selective and portable gas analysis.
F:P44 Humidity-Independent Oxide Chemiresistors with a Water-Blocking Tb4O7 Overlayer
SANG-MYEONG LEE, SEONG-YOUNG YOON, JUNG-HOO SEO, SEONG-YONG JEONG†, Division of Advanced Materials Engineering, Kongju National University, Cheonan, Republic of Korea
Humidity poisoning remains a critical obstacle to the practical application of metal oxide chemiresistors. Although various strategies have been explored to mitigate humidity interference, they are often accompanied by performance degradation, including low gas response, altered selectivity, and an excessive increase in sensor resistance. Here, we propose a bilayer design using a moisture-blocking Tb4O7 overlayer. The Tb4O7-coated bilayer sensor exhibited high acetone responses (dry air: 11.2; RH80%: 11.8), demonstrating excellent humidity tolerance. The high humidity endurance of the bilayer sensor is attributed to the moisture-blocking effect of hydrophobic Tb4O7. The general validity of the Tb4O7 overlayer coating was investigated using various sensing materials, including SnO2, ZnO, and Pd/SnO2. This strategy offers a practical route toward reliable chemiresistive gas sensors and robust artificial olfaction systems operating under humid conditions.
F:P45 Digital Light Processing of Nanocomposites Alumina-Zirconia Scaffolds
F.C. NUNES1, J.R. VERZA2, I.L. CAMARGO3, A.P. LUZ2, E.M.J.A. PALLONE1, 1University of São Paulo (USP/FZEA), Pirassununga, Brazil; 2Federal University of São Carlos (UFSCar), São Carlos, Brazil; 3Federal Institute of Education, Science and Technology of São Paulo (IFSP), Salto, Brazil
Digital Light Processing (DLP) for ceramic materials is an increasingly vital and promising additive manufacturing technique. This method allows for precise control over the final geometry, enabling the achievement of good shape fidelity and, more importantly for biomedical applications, hierarchical porosity. This finely tuned structural characteristic is widely recognized as playing a key and enabling role in successful bone tissue regeneration. In this study, we explored the fabrication of porous alumina/zirconia nanocomposites using the DLP technique. The resulting ceramic scaffolds exhibited highly defined structures with a network of interconnected pores. This pore connectivity is not merely a feature but an essential functional requirement for promoting cell adhesion, proliferation, and the necessary nutrient and waste migration within the entire three-dimensional structure. Furthermore, the excellent cell viability demonstrated by the fabricated samples highlights the considerable potential of the DLP technique. This approach is highly effective for producing functional ceramics with the complex and personalized shapes required for advanced biomedical applications, particularly in orthopedic and craniomaxillofacial reconstruction.
F:P46 Two-dimensional MoTe2 based Memristor and Memtransistor for Neuromorphic Computing
M. RADWAN1, A. MAYEEN SHAFI1, C. DIAS2, F. KHALID1, F. AHMED1, ZHIPEI SUN3, H. LIPSANEN1, 1Department of Electronics and Nanoengineering, Aalto University, Tietotie, Finland; 2IFIMUP, Departamento de Física e Astronomia, Faculdade de Ciências, Universidade do Porto, Porto, Portugal; 3QTF Centre of Excellence, Department of Applied Physics, Aalto University, Aalto, Finland
Neuro-based computing enabled by memristors and memtransistors has gained considerable attention over the years due to its ability to handle both data processing and storage. The demonstration of these devices using conventional materials has been limited by their low switching endurance, low scalability, and high-power consumption. Two-dimensional (2D) materials emerge as strong candidates for neuromorphic applications due to their unique electrical and optical properties such as high thermal stability, good mechanical flexibility, and high controllability over learning processes. In this study, we used multilayer mechanically exfoliated molybdenum ditelluride (MoTe2), without any prior modification or treatment, to fabricate single device that can operates as two-terminal memristor and a three-terminal memtransistor. The electrical characteristics of both memristor and memtransistor showed resistive switching behavior with excellent endurance over 400 cycles. They also demonstrated the ability to mimic biological synapses under applied voltage pulses. These stimuli strengthened or weakened the resistance of the devices to imitate two biological synapse processes (long-term potentiation/depression).
F:P47 Conduction Mechanisms Modeling in Bilayer PCMO-based Valence Change Memory Devices
JINHAO ZHANG, S. MENZEL, Z. MOOS, Peter Grünberg Institut 7, Forschungszentrum Jülich GmbH, Jülich, NW, Germany
Valence change memory (VCM) devices based on transition metal oxides are promising candidates for nonvolatile and neuromorphic applications. Among them, bilayer structures combining a tunnel oxide and a conductive oxide such as Pr0.7Ca0.3MnO3 (PCMO) offer improved uniformity and controllable switching behavior. However, the microscopic mechanisms governing their conduction and resistive switching remain insufficiently understood, particularly the role of trap-assisted tunneling (TAT) and interfacial oxygen exchange. Therefore, in this work, two compact models were developed, namely TAT-E for electron transport and TAT-H for hole transport, to simulate the conduction mechanism in bilayer W/WO3/PCMO/Pt structures using MATLAB. The simulations reproduce the experimental I-V characteristics and switching polarity, revealing that the conduction mechanism described by the TAT-H model is dominant in the devices under investigation. Parametric studies further show that the switching kinetics strongly depend on oxygen vacancy concentration, attempt frequency, migration barrier, and the permittivity contrast between the two oxides. These insights provide a physically consistent framework for optimizing PCMO-based VCM devices for low-power, energy-efficient neuromorphic computing.
F:P48 Integration of HZO Ferroelectric Weights on Flexible Substrates for Wearable Neuromorphic Systems
N. SAVOIA, A. FLASBY, A. MORTEZA, L. BÉGON-LOURS, ETHZ, Zürich, Switzerland
In the context of wearable healthcare, embedding neuromorphic hardware onto flexible substrates has the potential to enable ultra-low-power, real-time biosignal processing directly at the sensor interface. Resistive, non-volatile memories based on ferroelectric HfO2/ZrO2 nanolaminates (HZO) implement synaptic weights in analog AI hardware modules [1]. We report on the transfer of HZO thin films from rigid wafers onto polymer supports. Using anodic release, we successfully detached the multilayer structure and re-deposited it onto a polyethylene terephthalate (PET) substrate. In this talk, we address the corresponding challenges, such as thermal stress management: the mechanical constraints induced by the resist bake might lead to curling of the membrane. Another challenge is the need for a sacrificial Al/Cr layer between the Si wafer and the functional stack: we discuss how it affects the crystallization of HZO. We successfully demonstrate non-volatile, analog resistive switching in TiN / HZO (5 nm) / WOx / TiN devices crystallized on W/Al/Cr/SiO2//Si wafers prior to the transfer. This work represents a step toward mechanically compliant ferroelectric weights suitable for integration in wearable neuromorphic systems.
[1] Bégon-Lours et al. Adv. Electron. Mat (2024) 2300649
F:P49 SPICE Implementation of a Stochastic Compact Model for Memristive Nanowire Networks
E. MIRANDA, J. SUÑÉ, Universitat Autònoma de Barcelona, Cerdanyola del Valles, Spain; C. RICCIARDI, Politecnico di Torino, Turin, Italy; G. MILANO, Istituto Nazionale di Ricerca Metrologica, Turin, Italy
Memristive random networks based on Ag nanowires exhibit stochastic conductance dynamics that can be modeled through jump–diffusion Langevin equations. This approach describes a mean-reverting memory state driven by continuous fluctuations and discrete switching events. The stochastic evolution of the network arises from the random formation and rupture of multiple nanoscale junctions. Fluctuations are modeled by a Wiener process, while discrete jumps follow a Poisson process with Pareto-distributed amplitudes, capturing heavy-tailed statistics. The temporal evolution of the system is simulated in SPICE using the Method of Elementary Solvers (MES), yielding a compact stochastic model compatible with standard circuit design tools. The proposed framework enables the integration of nanowire-based random networks as functional elements in complex electronic architectures and can be extended to other physical and computational systems.
F:P50 All-Sputtered HfOx RRAM with Analog Resistive Switching for Neuromorphic Synapse and Cryoelectronic Applications
JIYONG WOO, School of Electronic and Electrical Engineering, Kyungpook National University, Daegu, Republic of Korea
As the demand for energy-efficient hardware to accelerate artificial intelligence algorithms continues to grow, neuromorphic computing inspired by the human brain has attracted great attention as a promising alternative to the conventional power-hungry von Neumann architecture. In neuromorphic systems, implementing artificial synapses—which represent the synaptic weights—is critical for training in pattern recognition applications. Thus, among various memory technologies, resistive random-access memory (RRAM) has been extensively explored to emulate the synaptic function. To date, RRAM synapses have been mostly demonstrated using atomic layer deposited HfO2 films. However, the use of relatively stoichiometric HfO2 restricts oxygen vacancy motion, often requiring long pulse widths in the microsecond range to update analog weight states. To address this challenge, we identified that field-driven vacancy migration for filament formation and dissolution is promoted in sputter-deposited HfOx films. This not only enabled analog switching characteristics but also allowed for weight updates with a pulse width as short as 100 ns. The analog RRAM exhibited linear weight update and stable multilevel retention even at a cryogenic temperature of 90 K.
F:P51 Radiation Tolerance in Compositionally Complex Alloys
J. VERMA, P. CHEKHONIN, A. WORBS, C. KADEN, M.O. LIEDKE, G. HLAWACEK, Helmholtz Zentrum Dresden Rossendorf, Dresden, Germany
Compositionally complex alloys (CCAs) represent a new paradigm in alloy design, distinct from conventional metallurgical approaches. Their complex chemistry gives rise to exceptional properties such as high mechanical strength, enhanced radiation resistance, and superior thermal stability, making them promising for structural applications in next-generation nuclear systems [1]. In Generation IV fission and future fusion reactors, materials must withstand extreme conditions, including high temperatures, high neutron fluxes, and, in fusion systems, embrittlement due to helium and hydrogen produced by neutron-induced transmutation. These gaseous species strongly influence irradiation-induced defect formation and evolution and require careful study. In this work, the radiation tolerance of CrFeMnNi alloys is investigated using Fe⁺ irradiation at 300 °C to 1, 3, and 10 dpa, analyzed by TEM and PAS. TEM reveals dense dislocation loops, while PAS provides insight into point defects and vacancy–dislocation complexes. An increase in average positron lifetime with temperature (low temp.) indicates neutral defects coupled with shallow traps. With increasing fluence, the defect landscape shifts toward more neutral positron trapping as the temperature dependence flattens.
F:P52 Direct Synthesis of MoS2 Electrocatalysts on the Surface of 3D-substrate for the Improved Reverse Electrodialysis
NAMJO JEONG1, HYUNOOK KIM2, KYOSIK HWANG1, JIHYUNG HAN1, EUNJIN JWA1, YUNCHEUL JUNG1, SUNNY KIM1, HANKI KIM1, 1SCI Convergence Research Center, Korea Institute of Energy Research, Jeju-si, Korea; 2Department of Energy and Environmental System Engineering, University of Seoul, Seoul, Korea
Reverse electrodialysis (RED) is the most commercially viable technology among various salinity gradient power generation methods, utilizing the potential generated by the salinity gradient between two solutions based on electrochemistry to produce electricity. The key to RED technology lies in the development of highly efficient ion-exchange membranes and electrochemical catalysts. In particular, excellent activity of electrochemical catalysts facilitates electron transfer at the electrode surface, thereby mximizing ion transport at the membrane surface. Therefore, the structural design and optimization of electrochemical catalysts are crucial for enhancing the efficiency of reverse electrodialysis. Molybdenum disulfide (MoS2) is widely considered as a promising two-dimensional material with remarkable electrochemical catalytic properties. Particularly, MoS2 structures are known for their high efficiency in reduction reactions. Various methods, including hydrothermal synthesis, solvothermal synthesis, and chemical vapor deposition (CVD), have been tried for the synthesis of MoS2 electrocatalysts.
F:P53 In-situ X-ray Tomography Characterisation of Liquid Phase Sintered BN Particle Dispersed SiC/SiC Composite under Bending Load
K. AKIL, Y. CHEN, T. HINOKI, A.J. LEIDE, University of Bath, Bath, UK
Silicon Carbide (SiC/SiC) ceramic matrix composites are a popular choice for first wall and blanket components in fusion reactors due to high temperature stability, resilience in corrosive environments, and low activation characteristics under neutron irradiation. An in-situ XCT three-point bend test was conducted on SiC/SiC composite samples fabricated via liquid phase sintering and hot pressing. The samples contained 50 vol.% BN particles in the matrix (rendering it ’weak’), and a pre-crack (notch) in two different orientations to study the effects of fibre reinforcement direction on damage evolution. The crack propagates from the tip of the notch and through the structure along the path of maximum stress, as the absence of interphase prevents crack deflection. The three-point bending test was conducted to failure, allowing for an assessment of deformation and stress responses in each sample. This is done via Digital Volume Correlation (DVC) to accurately measure internal displacements and strain fields within the material. From this we can study how plane orientation effects strain propagation, flexural strength, and material failure for SiC/SiC composites with high concentrations of BN particles.