Bi_2Sr_2Co_2O_y热电陶瓷的制备及其电学性能研究

Preparation and Electric Property of Bi_2Sr_2Co_2O_y Thermoelectric Ceramics

采用溶胶-凝胶法和固相反应法制备Bi2Sr2Co2Oy热电陶瓷。用XRD,SEM等表征技术研究了样品的物相及显微组织形貌;采用标准四探针法测试样品的电学性能。结果表明:样品为单相,组织均匀,为层片状结构,且具有明显的c轴择优取向。样品的电阻率-温度关系图显示,采用溶胶-凝胶法制备的样品在测试的温度范围内均表现了金属导电的特性,而采用固相反应法制备的样品的电子输运性质存在着半导体特性向金属特性的转变。

Bi2Sr2CO2Oy ceramics were prepared by sol-gel method and solid-state reactions. The phase and microstructure of the ceramics were analyzed by means of XRD and SEM. The temperature dependence of the electrical resistivity was detected with standard four probes method. The results show that the ceramics were single phase with layer microstructure homogeneous and oriented preferably to c-axis. The samples prepared by sol-gel method perform metallic-like behavior, while the semiconductormetal transition exists in the samples prepared bv solid-state reactions.