Synthesis of solid solutions, nanostructure control, and thermoelectric properties of perovskite-type stannates

采用聚合络合法和放电等离子烧结法制备了La掺杂钙钛矿型锡酸盐及其固溶体陶瓷，并对其热电性能进行了评价，以探索热电氧化物。Ba0.995La0.005SnO3陶瓷在1073 K时的无量纲优值最高，ZT=0.1。对于陶瓷，晶粒尺寸减小到平均约1微米对热导率的降低和品质因数的增加没有显着影响。与Ba 1-xLaxSnO 3相比，Sr 1-xLaxSnO 3中SnO 6八面体的倾斜导致其导电行为由简并型转变为热激活型，同时热导率也有所降低。

Ceramics of La-doped perovskite-type stannates and their solid solutions were prepared by the polymerized complex method and the spark plasma sintering method, and the thermoelectric properties were evaluated to explore thermoelectric oxides. The highest dimensionless figure of merit was obtained for a Ba0.995La0.005SnO3 ceramic showing ZT=0.1 at 1073 K. The grain size reduction to about 1 micrometer in average for the ceramic showed no significant effects on the decrease in the thermal conductivity and the increase in the figure of merit. Compared to Ba1-xLaxSnO3, the tilting of SnO6 octahedra for Sr1-xLaxSnO3 brought about the change in electrical conduction behavior from degenerate-type to thermal activation-type as well as the lowering in thermal conductivities.