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

Perovskite La1-xBixNiO3(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(NO3)3·6H2O,Bi(NO3)3·6H2O,Ni(NO3)3·5H2O 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 2.16×10-5W/(m·K2)at 973K,respectively.