( 上海交通大学 材料科学与工程学院
教育部高温材料及测试开放实验室, 上海 200030)
摘 要: 研究了掺杂B后CoSi化合物的微观组织及单晶的热电性能。结果表明：B在CoSi中的最大固溶度为0.4%（摩尔分数），CoSi化合物的晶格常数随着B含量的增加线性减小，当B含量达到其最大固溶度时晶格常数不再变化；电弧熔炼制备的CoSi1-xBx材料具有很多空洞和裂纹，单晶试样大大减少了组织上的缺陷；掺杂B后CoSi0.995B0.005单晶仍为N型传导，Seebeck系数的绝对值增加，电阻率下降，热导率升高；掺杂B后热电优值（ZT）增加。
关键字: B；固溶；晶格常数；CoSi单晶；热电性能
of B-doped CoSi
（ Key Laboratory of Ministry of Education for High Temperature Materials
and Testing, School of Materials Science and Engineering,
Shanghai Jiaotong University, Shanghai 200030, China）
Abstract: The microstructure and thermoelectric performance of B-doped binary compound cobalt monosilica were investigated. The results show that the solid solubility limit of B in CoSi is 0.4%(molar fraction). With the increase of the composition of B, the lattice parameter of CoSi linearly reduces and reaches a constant value when the content of B exceeds its solubility limit. There are lots of pores and flaws in CoSi1-xBx compounds prepared by arc melting, while defects in single crystal specimens are greatly reduced. B-doped CoSi single crystal shows N-type conduction. The substitution of B onto the Si sites causes an increase in the absolute value of Seebeck coefficient and the thermal conductivity, while the electrical resistivity decrease. The figure of merit (ZT) of B-doped CoSi single crystal slightly increases.
Key words: B; solid solution; lattice parameter; CoSi single crystal; thermoelectric performance
