Preparation And Thermoelectric Properties Of CoSb₃ And La_yNi_xCo_4-xSb₁₂

Thermoelectric material is a functional material of exchange heat with electricdirectly. So the thermoelectric setting can run quietly without mechanical drive and itis clean without pollution. It is one of the important materials of energy source. The paper research on thermoelectric material of CoSb3 and CoSb3-basedLayNixCo4-xSb12, which has skutterudite structure and used in middle temperature. Itis manufacture through mechanical grinding, and then sintered by spark plasmasintering. Analyze material structure by X-ray. Measure electrical parameter bystandard four-probe method (ULVAC-RIKO: ZEM-2) in a flowing He atmosphere.Measure thermo conductivity by laser flash method (TC-7000) in vacuum. Optimize technical conditions firstly. The optimal scale of ball-powder is 20:1and the optimal milling time is 5 hours. Using this result, Get the optimal sinteringtemperature is 873K. Also we try to separate diminish grain from synthesize, but theresult indicate it is unnecessary. Secondly, prepared LaxCo4Sb12 compound through filling rare earth La underthe optimal conditions. Through analyzing the thermoelectric properties, we find thatLa filling can reduce the thermal conductivity while keeping the electrical resistivityand the Seebeck coefficient. The LaxCo4Sb12 compounds achieved the maximum ZTvalue of 0.343 with x=0.9 at 773K. Lastly, prepared La0.9NixCo4-xSb12 compounds based on the result ofLaxCo4Sb12 compounds. Each La0.9NixCo4-xSb12 compound shows n-type behavior.The thermoelectric properties of La0.9NixCo4-xSb12 compounds indicate that properNickel substitute can reduce the electrical resistivity and the thermal conductivity.The La0.9NixCo4-xSb12 compounds achieved the maximum ZT value of 0.456 withx=0.4 at 773K. We achieve series optimal parameters through farther research step by step,which establish well foundation for continuing research.