The 14th Global Conference on Materials Science and Engineering
(CMSE 2025)

Abstract: The hardness of the contact surface of carbonitrided JIS-SCM420 low-alloy steel is higher than that of carburized one after the rolling-sliding contact fatigue test, which shows the greater resistance of the former to temper softening. The tangential force decreases until 1.0 × 10⁴ cycles and then increases gradually. Tribofilms are formed after 10⁴ cycles, and these cycles are fitted to the transition of the tangential forces. In the subzero-treated material, a crack formed vertically from a horizontal crack in the interior to the contact surface. The depth at which the horizontal crack formed corresponds to the maximum-shear-stress regime. In addition to the maximum-shear-strain regime, severe plastic deformation may generate horizontal microcracks in the interior of the specimen. Subsequently, the crack can propagate vertically to the rolling surface, where tensile stress is exerted, thus opening the subsurface crack. In the non-subzero-treated material, cracks formed on the surface and are connected to voids in the interior of the specimen. Solid dissolved nitrogen can create N₂ gas voids that change the direction of crack propagation.

Abstract: Flavins have emerged as promising photocatalysts for organic transformations, yet their practical application faces significant challenges, including synthetic accessibility, photostability, solubility, and tunable redox properties. We aims to establish general design principles for sustainable, high-performance flavin derivatives tailored for photocatalysis. By systematically exploring structural variations, we investigate how modifications to the flavin core—such as isoalloxazines, alloxazines, and deazaflavins—impact key properties like absorption spectra, triplet state energetics, and singlet oxygen generation. Our approach integrates experimental studies with quantum chemical calculations to optimize photophysical and redox properties, enabling the use of mild visible light sources and enhancing catalytic efficiency.

A major focus is on tuning singlet oxygen production for selective oxygenation reactions while minimizing unwanted side reactions. We also explore strategies to extend absorption into the red region, enabling photocatalysis with low-energy light and reducing substrate degradation. Additionally, we address photobleaching and stability issues by optimizing flavin structures and exploring alternative oxidants for catalyst regeneration. The results highlight the potential of tailored flavin derivatives for diverse photocatalytic applications, including sulfoxidations, benzylic oxidations, and energy-transfer cycloadditions. This work provides a roadmap for the rational design of flavin-based photocatalysts, bridging the gap between fundamental research and practical implementation in sustainable chemistry.

Keywords: Flavins, spectroscopy, photocatalysis, photochemistry, singlet oxygen

Acknowledgements: This work was supported by the Czech Science Foundation (Grant No 24-11386K) and by the research grant WEAVE-UNISONO UMO-2023/05/Y/ST4/00062, from The National Science Centre of Poland (NCN).

Abstract: Nanostructured materials evolved to a wider range of applications with the present progres of nanoscience and nanotechnologies, from medical to industrial, and from sensing to laser particle acceleration. While surface to volume ratio is getting larger, nanostructure dominant properties tends to be the morphology and surface related characteristics. Thus, we could talk about adsorption, catalytic processes and surface morphology related applications. A new cutting edge morphology related application of such nanostructured surfaces is particle acceleration by laser interaction with nanostructured materials. In recent years, High-Power lasers acceleration, particularly from thin metalic targets, become a competitor of clasic particle accelerators, and nanostructured targets have already proved their role in improving electron extraction efficiency by laser beams. However, if nanoporous materials, easier (and cheaper) to be produced, have already been started to show their process enhancement potential, crystaline matrials and aligned nanostructure areas are still on their beginning. Starting from oxide single-crystal nanowire layers previously used in different other applications (e.g. sensors, solar cells) and crystaline substrates, we explore here the possibility of using such ‘targets’ in laser particles acceleration. Preliminary simulations data on electron transport through such surfaces are compared with experimental data obtained from an electron beam of a classic accelerator, for a better understanding of laser acceleration elementary processes from such targets. Some preliminary laser acceleration tests were also performed and some results are presented and discussed here, with a particular focus on the laser extracted charge and generated electromagnetic fields, in corelation with the target properties.

Keywords: ZnO nanowires, nanostructured targets, laser acceleration, electron beam

Acknowledgements: We acknowledge funds from Ministry of Research, Innovation and Digitization / Institute of Atomic Physics from the National Research-Development and Innovation Plan III, through ELI-RO 30/2024 project and support of National Interest Infrastructure facility IOSIN—CETAL at INFLPR.

Abstract: A new dye-sensitized photovoltaic solar cell based on Nd₂Ru₂O₇ (NRO) pyrochlore was elaborated in the new stack materials Glass/FTO/TiO₂/Nd₂Ru₂O₇/hibiscus/Pt/FTO/Glass configuration and was characterized. Nd₂Ru₂O₇ pyrochlore oxide was elaborated as mesoporous nanoparticles dispersed in dimethylformamide (DMF) and deposited via spin coating onto the compact TiO₂ compact layer previously deposited on FTO-coated glass substrate. Hibiscus sabdariffa was used as absorbent dye on the NRO photoanode. The optical properties of the films showed highly performance of ~ 70% absorbance and a transmittance below ~ 50%. Dye-impregnated photoanodes have a high absorbance that covers the visible-IR spectral range (360 nm –1000 nm). These assembled photoanode materials give an open-circuit voltage Voc of 2.86 V. The efficiency of the natural dye solar cell (DSSC-N) with the new NRO photoanode increased by a factor of 1.35 compared with the simple TiO2 based solar cell reported in the literature. In this study, we present a novel configuration employing a natural dye extracted from hibiscus sabdariffa petals (from west Africa), integrated within a multilayered structure of FTO/TiO₂/Nd₂Ru₂O₇. Remarkably, our investigation has yielded a significant breakthrough, achieving an impressive energy conversion efficiency of 10.24%. Our study not only contributes to the fundamental understanding of DSSCs but also holds significant implications for practical applications in renewable energy technologies. Through a comprehensive analysis encompassing fabrication processes, characterization techniques, and performance evaluations, we provide valuable insights into the potential of our innovative solar cell design to address pressing energy challenges in the twenty-first century. Importantly, all these findings are original, showcasing the effectiveness of our novel approach for enhancing the performance of dye-sensitized solar cells.

Abstract: Additive manufacturing, an alternative to conventional manufacturing processes, is often considered a disruptive production method. However, it can also improve conventional manufacturing by providing a better way to produce and repair/remanufacture tools and enhance operational performance. Part manufacturers use tooling in their part production. Tooling made by additive manufacturing can, thus, incorporate additive manufacturing into the production chain. Production tools, dies, and molds are of great significance for the industrialization of new products and the operation of manufacturing plants. They play a key role in the manufacturing chain and highly affect the Time-To-Market, costs, lead time, operational efficiency, and quality. Tooling is highly competency-driven and determines the global competitiveness of the industry. In this invited speech:
• metal additive manufacturing of production tools/dies/molds by Laser-based Powder Bed Fusion (L-PBF) and Directed Energy Deposition with metal powder (DED-p) is addressed,
• the impact of these methods on the industrialization of new products and the operation of manufacturing plants is discussed,
• the influence of these methods on the Time-To-Market, costs, lead time, and quality is illustrated industrially,
• the properties of the metal powders used to make tools/dies/molds are discussed, and their impact on L-PBF and DED-p processes is illustrated,
• surface functionalization through DED-p is addressed and illustrated for two different applications in which friction coefficient and wear are of top priority, respectively, and
• topology optimization and its impact on tool/die/mold properties, performance, printing time, costs, and lead time are depicted.
The investigation shows that the material properties of tools/dies/molds made by L-PBF and DED-p are as good as those of the tools/dies/molds made by conventional methods in conventional tool/die/mold materials. L-PBF is currently appropriate for creating new tools/dies/molds, while DED-p benefits tool/die maintenance, repair, remanufacture, and surface functionalization. L-PBF is, furthermore, beneficial for hot-working tools/dies and injection molds. Additional research, development, and advanced engineering are required for cold-working tools/dies to make additive manufacturing competitive.

Keywords: Metal additive manufacturing, tools, dies, molds, laser-based powder bed fusion, directed energy deposition, metal powder, topology optimization, surface functionalization, properties, performance, operational efficiency

Abstract: Architected materials with hierarchical structure can be effectively used in the design of devices that must guarantee large ductility and energy absorption capability. Some recent results on metamaterials constituted by Triply Periodic Minimal Surfaces are presented. Architected materials realized with continuous microstructure potentially present advantages with respect to traditional lattice architected materials.

• The stiffness and sensitivity to buckling of the resulting microstructure is improved with respect to lattice metamaterials.
• TPMS divide the space in two non-interconnected subspaces, that can be exploited for functional purposes.
• Several shapes are available, that can be combined for optimal design.
• Hierarchical designs can be obtained distorting the original shapes with continuity.

Hierarchical design of metamaterials made of TPMS can be accomplished by:
• Thickness Grading.
• Hybridization of TPMS-based materials.
• Cell size grading.

A hierarchical design can be obtained using homogenization procedures in the static and dynamic regime. To this end the dependency of the main material properties some geometrical characteristics of the shell lattice is investigated.

Case studies related to medical implants are presented and the design based on homogenization procedure is validated by comparison with detailed simulations

Keywords: TPMS, Architected materials, Hierarchical structure, homogenisation

Abstract: Transparent electronic devices with tunable optical functionality require materials that combine high optical clarity with electrically controllable properties. In this study, we demonstrate aluminium nitride (AlN) thin films deposited by low-temperature plasma-enhanced atomic layer deposition (PEALD) at 300°C as a promising alternative for UV-transparent electronics. The 50 nm AlN films, characterized by X-ray diffraction as predominantly amorphous with smooth surface morphology, exhibit excellent dielectric properties with low leakage currents in metal-insulator-metal structures on both ITO/glass and TiN/Si substrates.

We found optical transmittance measurements to reveal exceptional UV transparency reaching 90% at 282 nm, coupled with remarkable field-tunable absorption. Under applied electric fields of 200 MV/m, optical modulation exceeds 50% in the deep-UV region while remaining negligible in the visible spectrum. Quantitative analysis indicates an electro-absorption coefficient of ~6×10^-5 cm·m/V, which we attribute to field-tunable defect states rather than conventional electro-optic mechanisms. These findings demonstrate that defect-engineered amorphous AlN enables electrically controllable UV transparency, opening new possibilities for next-generation transparent electronics and multifunctional optoelectronic devices.

Keywords: Thin film, atomic layer deposition, high-k, optical transmittance.

Abstract: High-performance graphene microwave absorption materials are highly desirable in daily life and some extreme situations. A simple technique for the direct growth of graphene as absorption fillers in wave-transmitting matrices is of paramount importance to bring it to real-world application. Herein, a simple chemical vapor deposition (CVD) route for the direct growth of edge-rich graphene (ERG) with tailored structures and tunable dielectric properties in porous Si₃N₄ ceramics using only methyl alcohol (CH₃OH) as precursor is reported. The large O/C atomic ratio of CH₃OH helps to build a mild oxidizing atmosphere and leads to a unique structure featuring open graphite nanosteps and freestanding nanoplanes, endowing the ERG/ Si₃N₄ hybrid with an appropriate balance between good impedance matching and strong loss capacity. Accordingly, the prepared materials exhibit superior electromagnetic wave absorption, far surpassing that of traditional CVD graphene and reduced graphene oxide-based materials, achieving an effective absorption bandwidth of 4.2 GHz covering the entire X band, with a thickness of 3.75 mm and a negligibly low loading content of absorbents.

Keywords: Graphene, chemical vapor deposition, microwave absorption.

Abstract: Gold-platinum (Au-Pt) alloy has aroused considerable attention due to its ultra-low magnetic susceptibility (MS) in testing mass (TM) on spacecraft. However, the effect of Au content on the properties of the alloy has not yet been understood. In this study, the composition design of Au-Pt alloy with ultra-low MS was achieved through density functional theory (DFT) and experimental methods. The elastic, thermal properties and electronic structure were systematically investigated, the composition range was further optimized and Au75Pt25 was determined to be the most suitable alloy for TM material. The phase composition of this alloy after cold rolling and solid solution was characterized, indicating a single-phase FCC structure. In addition, there is a good validation between the experimental Vickers hardness and the DFT results. This work provides new insights into the compositional optimization of Au-Pt alloys and lays the foundation for alloy development.

Keywords: Au-Pt alloy, ultra-low magnetic susceptibility, composition design, first principles, HAADF-STEM

Acknowledgements: This work was supported by the National Key R&D Program of China (2021YFC2202300), the National Natural Science Foundation of China (NSFC) (Grant No. 51974258), and National College Students Innovation and Entrepreneurship Training Program (S202210699134). The authors acknowledge Beijing PARATERA Tech CO., Ltd. for providing HPC resources that have contributed to the research results reported within this paper.

Abstract: High sensitivity, rapid response, low power consumption, and excellent stability are significant for practical applications of gas sensors. As the core component of gas sensors, sensitive materials require porous structures, which facilitates gas diffusion and adsorption as well as provides abundant active sites.This research focuses on improving gas-sensing capabilities by designing and fabricating various porous metal oxide semiconductors and next-generation porous carbon-based gas-sensitive materials. Through systematic investigations into the intrinsic relationships between material composition, microstructure, heterojunction types, and sensing performance, we have achieved highly sensitive, fast-response, low-power, and stable detection of target gases.

Keywords: Porous structure, enhanced gas response value, fast response, low working temperature,metal oxide, graphydine

Acknowledgements: This work was financially supported by the National Natural Science Foundation of China (62171359, 62571413 ), industrial research project of Science and Technology Department of Shaanxi Province (2021GY-227), Ningxia Natural Science Foundation Project (NO2024AAC02038).

Abstract: The kagome lattice provides a versatile platform where geometrical frustration, magnetism, and topological band structures intertwine to yield exotic quantum phenomena. A prototypical example is the antiferromagnetic Weyl semimetal Mn₃Sn, whose triangular spin configuration generates a large anomalous Hall and Nernst effect, chiral anomaly, and magnetic spin Hall effect. Yet, the intrinsic properties of Mn₃Sn have often been obscured by non-stoichiometry. Using a Bi flux-assisted recrystallization method, we obtained stoichiometric single crystals with record residual resistivity ratios (RRR > 23) and sharp magnetic phase transitions [1]. These high-quality samples reveal well-defined helical ordering between 250–280 K and suppression of the anomalous Hall effect below the helical transition, establishing a reliable platform for studying the interplay of helical magnetism and topological bands.

Building on this insight, we extended kagome physics to a new frontier by realizing for the first time a hetero-kagome bilayer compound, Zr₃Mn₃Sn₄Ga, where non-magnetic breathing Zr₃Sn₄ and magnetic Mn₃Ga kagome lattices coexist in a single crystalline framework [2]. Bulk magnetometry and neutron diffraction confirm an antiferromagnetic transition at Tₙ ≈ 87 K with commensurate ordering, while transport studies show metallic behavior with large magnetoresistance and Hall slope changes across Tₙ. Resonant photoemission identifies Zr 4d and Mn 3d states as key contributors, demonstrating strong coupling between lattice, spin, and electronic degrees of freedom.

Together, Mn₃Sn and Zr₃Mn₃Sn₄Ga illustrate how kagome systems—through both chemical precision and structural heterogeneity—enable exploration of emergent magneto-topological phenomena and broaden the landscape of quantum kagome materials.

Keywords: Kagome lattice, magnetism, Mn₃Sn, Zr₃Mn₃Sn₄Ga

References:
1. J Park, WY Kim, B Cho, WJ Choi, YS Kwon, J Seo, K Park, Nominal kagome antiferromagnetic Mn₃Sn: effects of excess Mn and its novel synthesis method, J. Mater. Chem. C, 2025,13, 11869-11878
2. J Park, B Cho, JS Oh, J Lee, T Rhee, D Lu, M Hashimoto, J Kim, K Park Zr₃Mn₃Sn₄Ga: A new hetero-kagome bilayer antiferromagnet” Scripta Materialia 264, (2025) 116701