Li Xiaofang, Yang Pengbo, Wang Yumei, Zhang Zongwei, Qin Dandan, Xue Wenhua, Chen Chen, Huang Yifang, Xie Xiaodong, Wang Xinyu, Yang Mujin, Wang Cuiping, Cao Feng, Sui Jiehe, Liu Xingjun, Zhang Qian
Department of Materials Science and Engineering, Institute of Materials Genome & Big Data, Harbin Institute of Technology, Shenzhen, Guangdong 518055, China.
Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
Research (Wash D C). 2020 Jan 30;2020:4630948. doi: 10.34133/2020/4630948. eCollection 2020.
The solubility range of interstitial Ni in the ZrNi Sn half-Heusler phase is a controversial issue, but it has an impact on the thermoelectric properties. In this study, two isothermal section phase diagrams of the Zr-Ni-Sn ternary system at 973 K and 1173 K were experimentally constructed based on the binary phase diagrams of Zr-Ni, Zr-Sn, and Ni-Sn. The thermodynamic equilibrium phases were obtained after a long time of heating treatment on the raw alloys prepared by levitation melting. Solubilities of < 0.07 at 973 K and < 0.13 at 1173 K were clearly indicated. An intermediate-Heusler phase with a partly filled Ni void was observed, which is believed to be beneficial to the lowered lattice thermal conductivity. The highest ZT value~0.71 at 973 K was obtained for ZrNiSn. The phase boundary mapping provides an important instruction for the further optimization of ZrNiSn-based materials and other systems.
间隙Ni在ZrNiSn半赫斯勒相中的溶解度范围是一个有争议的问题，但它对热电性能有影响。在本研究中，基于Zr-Ni、Zr-Sn和Ni-Sn的二元相图，通过实验构建了Zr-Ni-Sn三元体系在973K和1173K时的两个等温截面相图。对通过悬浮熔炼制备的原始合金进行长时间热处理后，获得了热力学平衡相。结果清楚地表明，在973K时溶解度<0.07，在1173K时溶解度<0.13。观察到一种具有部分填充Ni空位的中间赫斯勒相，据信这有利于降低晶格热导率。ZrNiSn在973K时获得的最高ZT值约为0.71。相界映射为进一步优化ZrNiSn基材料和其他体系提供了重要指导。
