(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: 采用基于第一性原理的密度泛函理论全势线性缀加平面波法计算CoSi的电子结构及Si侧Al置换掺杂的CoSi0.875Al0.125的电子结构并分析两者的电子结构特征。 结果表明： CoSi为典型的半金属化合物， 在费米面处价带和导带存在部分重叠且在费米面处电子能态密度值比较低， 因此其导电性能相对金属的导电性能稍微差一些； 在理论计算的基础上， 选择制备CoSi和CoSi0.88Al0.12两种单晶并测试了两种单晶在300～1 000 K之间的塞贝克系数、 电阻率及300～480 K之间的热导率。 随着温度的升高， CoSi的塞贝克系数变化不大， 而CoSi0.88-Al0.12的塞贝克系数呈降低的趋势， 且存在一由正向负的转变温度， 随着温度的升高， CoSi和CoSi0.88Al0.12的电阻率都增大， CoSi的热导率逐渐下降， 而CoSi0.88Al0.12的热导率先下降然后上升。
关键字: 热电材料; 电子结构; Al掺杂; 传输性能
（ Key Laboratory for High Temperature Materials and Testing, Ministry of Education, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200030, China）
Abstract: By using the linearized augmented plane wave(LAPW) based on the density functional theory(DFT) of the first principles, the calculations of the electronic structures of CoSi and CoSi0.875Al0.125 were performed, the electronic structures of CoSi and CoSi0.875Al0.125 were analyzed and the CoSi and CoSi0.88Al0.12 single crystals were prepared. The temperature dependences of Seebeck coefficient and electrical resistivity at 300-1 000 K, and thermal conductivity at 300-480 K were characterized. The intrinsic relations between electronic structures of CoSi and CoSi0.875Al0.125 and transport performance of CoSi and CoSi0.88Al0.12 were discussed respectively.
Key words: thermoelectric materials; electronic structure; Al doping; transport performance
