自燃法制备N型Bi掺杂LaNiO_3氧化物及其热电性能研究

以柠檬酸为螯合剂,各种硝酸盐为原料,采用简单的自燃法制备了金属Bi掺杂的N型钙钛矿结构的La1-xBixNiO3(x=0、0.025、0.05、0.075、0.1、0.15)热电材料前驱粉。前驱粉经煅烧、球磨、冷压、烧结等工艺获得块体材料。通过X射线衍射和扫描电镜观察等方法对样品的结构与形貌进行了分析表征。在573～1073K内测试了材料的电阻率和Seebeck系数,结果表明,该材料显示了较好的热电性能,掺杂Bi有助于显著降低材料的电阻率,优化材料的热电性能,其中试样La0.9Bi0.1NiO3组分材料在973K时的电阻率ρ=3.9606mΩ.cm,Seebeck系数S=-29.253μV/K,热电转换功率因子值p=2.16×10-5W/(m.K2)。

Self-ignition Route to N-type Thermoelectric Oxides of Bi-doped LaNiO_3 and Their Thermoelectric Properties

Perovskite La_(1-x)Bi_xNiO_3(x=0,0.025,0.05,0.075,0.1,0.15)thermoelectric powders have been prepared by a simple self-ignition and calcinations route,using the analytic grade La(NO_3)_3·6H_2O,Bi(NO_3)_3·6H_2O,Ni(NO_3)_3·5H_2O as reagents.The citric acid is used as chelating agent.The stripy samples are obtained by cold compacting and sintering process after the powders ground by ball milling.The microstructures of the ceramic samples are characterized by X-ray diffraction and scanning electron microscopy.The electrical resistivities and Seebeck coefficients are studied at the temperature ranging from 573K to 1073K.The results show that the materials display favorable thermoelectric properties;the electrical resistivity decreases significantly by Bi-doped method;the material thermoelectric properties are optimized obviously;the electrical resistivity(ρ),Seebeck coefficient(S) and power factor(p)of Bi-doped(0.1) sample are 3.9606mΩ·cm,-29.253μV/K,and 2.16×10 ~(-5)W/(m·K~2)at 973K,respectively.