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Cr5Si3B and Hf5Si3B:New MAB phases with anisotropic electrical,mechanical properties and damage tolerance

Journal of Materials science & technology 2018年第8期34卷 1441-1448页

作者： Yanchun Zhou Huimin Xiang Fu-Zhi Dai Zhihai Feng Science and Technology on Advanced Functional Composite Laboratory Aerospace Research Institute of Materials&Processing TechnologyNo.1 South Dahongmen RoadBeijing 100076China

Through a combination of electronic structure, chemical bonding and mechanical property investigations, anisotropic electrical and mechanical properties, and damage tolerant ability of MAB phases CrsSi3 B and HfsSi3B are predicted. The anisotropic electrical conductivity is due to the anisotropic distribution of Cr in CrsSiaB and Hf in HfsSi3B, which mainly contribute to the electrical conductivity. The anisotropic mechanical properties are underpinned by the anisotropic chemical bonding within the crystal structures of CrsSi3B and HfsSi3B. The high stiffness is determined by the strong covalent-ionic Crl--B--Crl and Crl--Si bonds in CrsSi3B and the ionic-covalent Hfl--B--Hfl and Si--B bonds in HfsSi3B; while the low shear deformation resistance is attributed to the presence of metallic Cr--Cr, Hf--Hf and Si--Si bond. Based on the low Pugh＇s ratio, CrsSi3B and Hfs Si3B are predicted tolerant to damage. The possible cleavage plane is （0001） and the possible slip systems are 〈1 100〉1{11 20} and 〈11 20〉1{0001} for both CrsSi3B and HfsSi3B.

关键词： MAB phases CrsSi3B and HfsSi3 BFirst-principles calculations Mechanical properties Chemical bonding

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BaMgSiO4-based composites with photochromic and persistent luminescent behaviors for advanced anti-counterfeiting applications

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Ceramics International 2025年

作者： Liu, Meng Shao, Jie Li, Xiyang Guo, Yu Lu, Chunxiao Ke, Shanjun Sun, Haiqin Zhang, Qiwei University Engineering Research Center of Advanced Functional Materials and Intelligent Sensing Guangxi Guilin541004 China College of Physics and Technology Guangxi Normal University Guilin541004 China High-Tech Co. Ltd. Baotou014010 China Inner Mongolia Key Laboratory of Advanced Ceramic Materials and Devices School of Materials Science and Engineering Inner Mongolia University of Science and Technology Baotou014010 China Guangxi Oceano Ceramics Co. Ltd. Wuzhou543300 China

Photochromic (PC) materials with persistent luminescent (PersL) behaviors show potential applications in advanced anti-counterfeiting and optical storage fields. However, it is difficult to simultaneously achieve PC and PersL properties in a single host, due to their different positions of defect energy levels between conduction band and valence band. In this work, a new strategy is proposed to obtain two features by constructing two-phase composites of photochromic BaMgSiO4:Eu2+ and long afterglow Sr2MgSi2O7:Eu2+/Dy3+ materials. The optimized composite sample not only exhibited the reversible white-purple color change by alternating 365 nm and 520 nm light irradiation, but also showed the blue afterglow luminescence for more than 20 min. The designed anti-counterfeiting component based on the composite sample provides a higher-level security anti-counterfeiting than conventional PC materials. These results may facilitate more innovative designs for future dynamic anti-counterfeiting and optical storage applications. © 2025 Elsevier Ltd and Techna Group S.r.l.

关键词： Photochromism

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Tailoring structural, mechanical, and electronic properties of (Ti0.25Ta0.25Zr0.25Nb0.25-xLax)C high-entropy carbide ceramics via rare-earth La incorporation: A comprehensive first-principles study

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Ceramics International 2025年

作者： Wang, Zhipeng Yu, Zhaowen Zhang, Linkun Liu, Feng Huang, Lan Wang, Yan Tan, Liming Wang, Zi Ma, Li Tang, Pingying School of Materials Science and Engineering Dongguan University of Technology Guangdong Province Dongguan523808 China State Key Laboratory of Advanced Design and Manufacturing Technology for Vehicle Hunan University Hunan Province Changsha410082 China State Key Laboratory for Powder Metallurgy Central South University Hunan Province Changsha410083 China Guangxi Key Laboratory of Functional Information Materials and Intelligent Information Processing Nanning Normal University Guangxi Province Nanning530001 China

High-entropy carbide ceramics (HECCs) exhibit exceptional material properties, but their underlying physical mechanisms are underexplored. This study utilizes first-principles calculations to examine the influence of rare-earth La on the structural, mechanical, dislocation, and electronic properties of (Ti0.25Ta0.25Zr0.25Nb0.25-xLax)C (x = 0∼18.75 %) HECCs. Key parameters, including formation enthalpy, lattice distortion, elastic constants, mechanical modulus, and density of states, are systematically analyzed as a function of La content. Results show that La preferentially substitutes Nb sites, forming thermodynamically stable rock-salt structures. Increased La content induces severe lattice distortion, reduces resistance to bulk, elastic, and shear deformation, and enhances ductility while decreasing brittleness. La incorporation also lowers Vickers hardness and yield strength, weakening crack resistance. Notably, (Ti0.25Ta0.25Zr0.25Nb0.0625La0.1875)C exhibits minimal energy factors and maximum dislocation width, facilitating dislocation nucleation and twinning. A rightward shift and reduced peak heights in valence band of total density of states curves with increasing La content indicate enhanced electron delocalization and reduced brittleness. These findings highlight the potential of La substitution to tailor structural, mechanical, and electronic properties in (Ti0.25Ta0.25Zr0.25Nb0.25-xLax)C HECCs, offering insights for designing ductile HECCs. © 2025 Elsevier Ltd and Techna Group S.r.l.

关键词： Vickers hardness

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Triazine containing additional N sites to prepare branched poly(terphenyl piperidine) membranes for high-temperature proton exchange membrane fuel cells

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Journal of Membrane science 2025年 731卷

作者： Shen, Yan-Hong Liu, Meng-Long Mao, Zhe-Yu Zhou, Tao Han, Xu Song, Ying-Yu Wu, Yong Gao, Ying He, Wen-Wen School of Chemistry and Life Science Advanced Institute of Materials Science Changchun University of Technology Changchun130012 China Department of Chemistry Northeast Normal University Changchun130024 China Jilin Provincial Key Laboratory of Straw-Based Functional Materials Institute for Interdisciplinary Biomass Functional Materials Studies Jilin Engineering Normal University Changchun130052 China

High-temperature proton exchange membrane fuel cells (HT-PEMFCs) enable simplified water/heat management and enhanced energy efficiency. However, the trade-off between proton conductivity and mechanical properties of high-temperature proton exchange membranes (HT-PEMs) is a challenge in this field. In this work, introduction of 2,4,6-triphenyl-1,3,5-triazine (TPTA) containing additional N sites as a branched agent, the TPTA-branched poly(terphenyl piperidine) polymers (tPTP-x) are synthesized by superacid-catalyzed reactions. The test results show that the tPTP-2 membrane reaches a proton conductivity of 137.5 mS cm−1 (180 °C), and also achieves a tensile strength of 5.4 MPa. Assembled H2–O2 fuel cell with tPTP-2 membrane exhibits a high power density of 655.4 mW cm−2. Theoretical calculations show that TPTA has a strong binding energy to phosphoric acid (PA), which allows the tPTP-x series membranes to absorb more PA. It provides a denser and more continuous hydrogen bonding network for proton transfer, hence increasing the proton conductivity of membranes. At the same time, the rigid structure of TPTA also maintains good mechanical properties of the membrane. As a result, this work provides a simple and feasible strategy for the development and practical application of high-performance HT-PEMs. © 2025

关键词： Tensile strength

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First demonstration of possible two-dimensional MBene CrB derived from MAB phase Cr_2AlB_2

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Journal of Materials science & technology 2018年第11期34卷 2022-2026页

作者： Haiming Zhang Huimin Xiang Fu-zhi Dai Zhili Zhang Yanchun Zhou Science and Technology on Advanced Functional Composite Laboratory Aerospace Research Institute of Materials & Processing Technology School of Mechanical and Electrical Control Engineering Beijing Jiaotong University

In this communication, the possibility for the preparation of two-dimensional MBene CrB from MAB phase Cr2AlB2 is demonstrated for the first time. Herein M is a transition metal, A is a group IIIAor IVA element and B is boron; MAB phases are layered transition metal ternary borides, MBene is used to emphasize the loss of A group element from the parent MAB phases and to highlight the 2 D nature. The possible 2 D CrB nano sheets are prepared by selectively etching out Al layers from Cr2AlB-2 by immersing the Cr2AlB2 powders in dilute HCl solution at room temperature. The as-prepared 2 D CrB nano sheets are examined using X-ray diffraction and scanning electron microscopy and energy dispersive X-ray spectroscopy（EDS）. In addition, different structure models are built to explain the observed *** discovery in this work opens a door to the synthesis of a large number of new 2 D MBenes from MAB phases.

关键词： 2D CrB nano sheets MBene MAB phases Exfoliation Transition metal borides

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Pairing phase diagram for electron-doped cuprates in the square-lattice t − U − V Hubbard model

arXiv

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arXiv 2025年

作者： Cao, Zhangkai Tan, Shuning Liu, Ji Yang, Xiaosen Ying, Tao Tang, Ho-Kin Yip, Cho-Tung School of Science Harbin Institute of Technology Shenzhen518055 China Key Laboratory for Microstructural Material Physics of Hebei Province School of Science Yanshan University Qinhuangdao066004 China Shenzhen Key Laboratory of Advanced Functional Carbon Materials Research and Comprehensive Application Shenzhen518055 China Department of Physics Jiangsu University Zhenjiang212013 China School of Physics Harbin Institute of Technology Harbin150001 China

Motivated by significant discrepancies between experimental observations of electron-doped cuprates and numerical results of the Hubbard model, we investigate the role of nearest-neighbor (NN) electron interactions V by studying the t− U − V model on square lattices. Upon doping δ= 0.153, by using constrained path quantum Monte Carlo (CPQMC) method, we find that NN electron attraction V can notably drive an exotic p-wave spin-triplet pairing, while the NN electron repulsion V will suppress the dx2−y2-wave (d-wave) pairing and triggers the dxy-wave pairing. Especially in the intermediate coupling regime, as NN repulsion increases, the intensity of dxy-wave pairing also increases, further suppressing the presence of d-wave pairing, which may help explain the notable suppression of d-wave pairing in electron-doped cuprate superconductors. Besides the pairing phase, we also find that the NN electron attraction V has no significant effect on spin density wave (SDW) and charge density wave (CDW), but repulsion V significantly enhanced CDW and suppressed SDW. Our study suggests the t−U −V Hubbard model can serve as the minimal model to capture the essential physics of the electron-doped cuprates. Notably, for V/U ∼ 1/4 − 1/3, the results align more closely with the experimentally observed behavior of electron-doped systems, potentially explaining the shrinkage of d-wave superconductivity region and the decrease of superconducting temperature. © 2025, CC BY.

关键词： Hubbard model

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Multifunctional composite Metamaterials for Ultra–Wideband Microwave Absorption, Radar Stealth, Antibacterial and Adsorption–Purification

SSRN

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SSRN 2025年

作者： Yang, Xin Wang, Hong Zhu, Tong Su, Xiao Lin, Zequn Xiao, Liang Liu, Pingan Yu, Qianqian Wang, LinGe South China Advanced Institute for Soft Matter Science and Technology School of Emergent Soft Matter Guangdong Provincial Key Laboratory of Functional and Intelligent Hybrid Materials and Devices Guangdong Basic Research Center of Excellence for Energy and Information Polymer Materials State Key Laboratory of Luminescent Materials and Devices South China University of Technology Guangzhou510640 China School of Materials Science and Engineering South China University of Technology Guangzhou510640 China

Electromagnetic wave absorption materials have significant application value in modern electronic devices, communication systems, and aerospace fields. With the continuous advancement of technology, the demand for materials with efficient wave absorption performance and wide bandwidth is steadily increasing. This study focuses on heterostructure design and multi–component strategies, which have been proven to effectively enhance the material's reflection loss and absorption bandwidth. By employing electrostatic self–assembly and hydrazine reduction techniques, silver (Ag) nanoparticles were successfully anchored onto reduced graphene oxide (RGO)/Ti3C2Tx MXene hybrids. The MXene/RGO/Ag (MRAg) hybrid, with only a 20 wt% filler content, exhibits outstanding wave absorption performance, with a minimal reflection loss (RLmin) of –47.28 dB (2.2 mm, 8.0 GHz) and a maximum effective absorption bandwidth (EAB) of 8.08 GHz (2.2 mm), achieving an absorption rate of 99.998%. The excellent wave absorption performance arises from multiple mechanisms, including polarization effects, impedance matching, conductive losses, quarter–wavelength effects, multiple reflections, metamaterial characteristics, quasi-antenna effects, and magnetic losses. Notably, the radar cross–section (RCS) of the MRAg composite material achieves a maximum reduction of 35.6 dB•m2, indicating excellent radar stealth performance. Additionally, MRAg demonstrates excellent antibacterial and adsorption–purification properties. The study of MRAg wave absorbents provides valuable theoretical and practical contributions to fields such as radar stealth, satellite communication, and electromagnetic interference (EMI) shielding, while also offering new insights for the development of multifunctional wave absorbents. © 2025, The Authors. All rights reserved.

关键词： Radar shielding

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Shear anisotropy： Tuning high temperature metal hexaborides from soft to extremely hard

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Journal of Materials science & technology 2017年第11期33卷 1371-1377页

作者： Yanchun Zhou Fuzhi Dai Huimin Xiang Bin Liu Zhihai Feng Science and Technology on Advanced Functional Composite Laboratory Aerospace Research Institute of Material & Processing Technology Beijing 100076China School of Materials Science and Engineering Shanghai University Shanghai 200444 China

Easy machining into sharp lending edge, nose tip and complex shape components plays a pivotal role in the application of ultrahigh temperature ceramics in hypersonic vehicles, wherein low and controllable hardness is a necessary parameter to ensure the easy machinability. However, the mechanism that driving the hardness of metal hexaborides is not clear. Here, using a combination of the empirical hardness model for polycrystalline materials and density functional theory investigation, the hardness dependence on shear anisotropic factors of high temperature metal hexaborides has been established. It has come to light that through controlling the shear anisotropic factors the hardness of polycrystalline metal hexaborides can be tailored from soft and ductile to extremely hard and brittle, which is underpinned by the degree of chemical bonding anisotropy, i.e., the difference of B-B bond within the B;octahedron and that connecting the B;octahedra.

关键词： Microhardness Electronic structure Elastic constant Borides Structural ceramics

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Undamped soliton-like domain wall motion in sliding ferroelectrics

arXiv

引用

arXiv 2025年

作者： Shi, Yubai Gao, Yuxiang He, Ri Wang, Hua Zhang, Binwen Zhong, Zhicheng CAS Key Laboratory of Magnetic Materials and Devices Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology Ningbo Institute of Materials Technology and Engineering Chinese Academy of Sciences Ningbo315201 China College of Materials Science and Opto-Electronic Technology University of Chinese Academy of Sciences Beijing100049 China Center for Quantum Matter School of Physics Zhejiang University Hangzhou310058 China School of Artificial Intelligence and Data Science University of Science and Technology of China Hefei230026 China Suzhou Institute for Advanced Research University of Science and Technology of China Suzhou215123 China Fujian Key Laboratory of Functional Marine Sensing Materials Center for Advanced Marine Materials and Smart Sensors College of Material and Chemical Engineering Minjiang University Fuzhou350108 China

Sliding ferroelectricity, which is a unique polarity recently discovered in bilayer van der Waals materials, achieves polarization switching through in-plane interlayer sliding. The unique mechanism, combining intralayer stiffness and interlayer slipperiness, leads to wider domain walls (DWs) and faster DW motion compared to conventional ferroelectrics. Herein, using machine-learning-assisted molecular dynamics simulations and field theory analysis, we find the DW in classical sliding ferroelectric bilayer 3R-MoS2 system exhibits uniformly accelerated motion under an external field, like the Newtonian particle with undamped motion. Remarkably, DW velocity remains constant even after the external field removal, completely deviating from the velocity breakdown observed in conventional ferroelectrics. We further propose an experimental approach to validate this undamped soliton-like DW behavior in sliding ferroelectric systems. Copyright © 2025, The Authors. All rights reserved.

关键词： Van der Waals forces

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Preparation and molten salts corrosion behavior of high-entropy（Ca,Sr,Ba） TMO3（ TM = Zr, Hf and Ta）: Promising protecting materials of reference electrode for metal smelting through fused salts electrolysis

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Corrosion Communications 2021年第3期3卷 10-22页

作者： Shuaihang Qiu Huimin Xiang Fu-Zhi Dai Hailong Wang Yanchun Zhou School of Materials Science and Engineering Zhengzhou University Science and Technology on Advanced Functional Composite Laboratory Aerospace Research Institute of Materials & Processing Technology

The protecting materials of reference electrode with good corrosion resistance to molten salts play vital roles in realizing smelting of refractory and rare earth metals through fused salts electrolysis. BaZrO3has been considered as a candidate protecting material of reference electrode for its good chemical stability and high-temperature corrosion resistance. However, the unsatisfactory corrosion resistance to molten salts hinders its practical application. In order to enhance the corrosion resistance to molten salts, three perovskite structured high-entropy oxides HE（Ca,Sr,Ba） TMO3including（Ca,Sr,Ba）(Zr,Hf)O3,（Ca,Sr,Ba）(Zr,Ta)O3and（Ca,Sr,Ba）(Zr,Hf,Ta)O3, were designed and prepared in this work. The as-prepared HE（Ca,Sr,Ba）(Zr,Hf)O3and（Ca,Sr,Ba）(Zr,Hf,Ta)O3ceramics are single-phase, while the as-prepared HE（Ca,Sr,Ba）(Zr,Ta)O3ceramic contains 11.6 vol.% of（Ca,Sr,Ba）2Ta2O7. These HE（Ca,Sr,Ba） TM O3ceramics possess better corrosion resistance to molten Na Cl-KCl salts than Ba Zr O3, among which（Ca,Sr,Ba）(Zr,Hf,Ta)O3shows the best corrosion resistance to molten Na Cl-KCl salts. The mass loss per unite area of HE（Ca,Sr,Ba）(Zr,Hf,Ta)O3after corrosion by molten Na Cl-KCl salts at 800 °C for 8 h is mere 2.6 ×10-6g/mm2which is ca. 1/60 of that of BaZrO3( ～1.7 ×10-4g/mm2), and its surface after corrosion is plain and smooth without any new phase detectable after corrosion. It also exhibits better corrosion resistance to molten Na F-KF salts than BaZrO3. The mass loss per unite area after corrosion by molten Na F-KF salts at 800 °C for 8 h is only 2.9 ×10-5g/mm2which is smaller than that of BaZrO3(3.6 ×10-5g/mm2), the corrosion caused by molten Na F-KF salts only occurs on the surface and the thickness of the corrosion layer is mere ～8 μm, being less than 1/10 of that of BaZrO3（～100 μm）. These results indicate that the three HE（Ca,Sr,Ba） TMO3, especially（Ca,Sr,Ba）(Zr,Hf,Ta)O3, are promising as protecting materials of reference electrode for the smelting of refractory and rar

关键词： High-entropy ceramics Perovskite-oxide Corrosion resistance Metal smelting Molten NaCl-KCl salts Molten NaF-KF salts

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