具有多功能特性的新型熵稳定萤石氧化物
Novel entropy-stabilized fluorite oxides with multifunctional properties
AI总结：
本研究通过固相反应合成了一系列新型熵稳定萤石氧化物，证实其构型熵主导的相稳定性，并发现该材料在热导率、光学带隙和电学性质方面表现出适用于热障涂层和光催化等多功能应用的潜力。
摘要：
自2015年发现岩盐结构熵稳定（ES）(MgCoNiCuZn)O以来，开发以构型熵主导相稳定性的新型高熵氧化物已成为研究热点。本文报告了一组新型熵稳定萤石氧化物：Zr0.2Hf0.2Ce0.2Sn0.2Mn0.2O2-δ、Zr0.2Hf0.2Ti0.2Mn0.2Ce0.2O2-δ、Zr0.225Hf0.225Ti0.225Mn0.225Ce0.1O2-δ和Zr0.2Hf0.2Ti0.2Mn0.2Ce0.1Ta0.05Fe0.05O2-δ，采用标准固相反应合成。通过X射线衍射、扫描电子显微镜和X射线光电子能谱技术研究了这些化合物的结构、微观结构和化学性质。循环热处理证实了构型熵主导的相稳定性及化合物的熵稳定特性。阳离子半径和氧化态的不匹配是实现单相萤石结构的关键因素。此外，讨论了包括热导率、光学带隙、磁性质和阻抗谱在内的物理性质筛选。在300K时观察到1.4-1.7 Wm-1K-1的热导率，且在宽温度范围（300K-1073K）内基本保持不变，有利于热障涂层应用。这些ES样品具有1.6-1.8 eV的光学带隙，可实现可见光谱范围内的光吸收，有望用于光催化应用。熵稳定样品的阻抗谱数据揭示了在298K-423K温度范围内存在具有小活化能（0.3-0.4 eV）的电子贡献。这些ES萤石体系的观察结果表明，通过进一步优化可实现多功能应用，并证实了熵稳定氧化物具有高度的化学多样性。
英文摘要：
Development of new high-entropy oxides having configurational entropy dominating the phase stability has become a hot topic since the discovery of rock salt structure entropy-stabilized (ES)(MgCoNiCuZn)O in 2015. Herein, we report a set of novel entropy-stabilized fluorite oxides: Zr0.2Hf0.2Ce0.2Sn0.2Mn0.2O2-δ, Zr0.2Hf0.2Ti0.2Mn0.2Ce0.2O2-δ, Zr0.225Hf0.225Ti0.225Mn0.225Ce0.1O2-δ, and Zr0.2Hf0.2Ti0.2Mn0.2Ce0.1Ta0.05Fe0.05O2-δ synthesized using standard solid-state reaction. These compounds have been investigated using X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy techniques to discern their structural, microstructural, and chemical properties. The configurational-entropy dominated phase stability and hence the entropy stabilization of the compounds is confirmed by cyclic heat treatments. The mismatch in the ionic radii and oxidation state of the cations are the key factors in achieving a single-phase fluorite structure. Further, screening of physical properties including thermal conductivity, optical band gap, magnetic properties, and impedance spectroscopy is discussed. Thermal conductivity of 1.4-1.7 Wm-1K-1 is observed at 300 K and remains mostly invariant across a wide temperature range (300K-1073K), favorable for thermal barrier coating applications. These ES samples have an optical band gap of 1.6-1.8 eV, enabling light absorption across the visible spectrum and hence could be promising for photocatalytic applications. The impedance spectroscopy data of the entropy-stabilized samples reveal the presence of electronic contributions with small activation energy (0.3-0.4 eV) across a temperature range of 298K-423K. These observations in ES fluorite systems show potential for their multifunctional applications via further optimization and confirm the great chemical versatility of entropy-stabilized oxides.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
