Department of Physics, University of South Florida, Tampa, FL 33620, USA.
Materials Measurement Science Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA.
Dalton Trans. 2023 Jun 20;52(24):8316-8321. doi: 10.1039/d3dt01192e.
Single crystals of the quaternary chalcogenide BaCuGdTe were obtained by direct reaction of elements allowing for a complete investigation of the intrinsic electrical and thermal properties of this previously uninvestigated material. The structure was investigated by high-resolution single-crystal synchrotron X-ray diffraction, revealing an orthorhombic crystal structure with the space group Although recently identified as a semiconductor suitable for thermoelectric applications from theoretical analyses, our electrical resistivity and Seebeck coefficient measurements show metallic conduction, the latter revealing strong phonon-drag. Temperature dependent hole mobility reveals dominant acoustic phonon scattering. Heat capacity data reveal a Debye temperature of 183 K and a very high density of states at the Fermi level, the latter confirming the metallic nature of this composition. Thermal conductivity is relatively high with Umklapp processes dominating thermal transport above the Debye temperature. The findings in this work lay the foundation for a more detailed understanding of the physical properties of this and similar multinary chalcogenide materials, and is part of the continuing effort in investigating quaternary chalcogenide materials and their suitability for use in technological applications.
通过元素直接反应获得了四元硫属化物 BaCuGdTe 的单晶，从而可以对该之前未研究过的材料的固有电学和热学性能进行全面研究。通过高分辨率单晶同步加速器 X 射线衍射对结构进行了研究，揭示了具有空间群的正交晶体结构。尽管最近从理论分析中确定为适合热电应用的半导体，但我们的电阻率和 Seebeck 系数测量显示出金属导电性，后者显示出强烈的声子拖拽。温度相关的空穴迁移率显示出主要的声学声子散射。热容数据揭示了德拜温度为 183 K，费米能级处的态密度非常高，后者证实了该组成的金属性质。热导率相对较高，德拜温度以上的热输运主要由 Umklapp 过程主导。这项工作的结果为更详细地了解该和类似的多元硫属化物材料的物理性质奠定了基础，并且是研究四元硫属化物材料及其在技术应用中适用性的持续努力的一部分。
