Journal of the Japan Institute of Metals and Materials · 2008 · 16 citations · 11 references
Natural SciencesMaterials SciencePhysicsElectronic MaterialsMaterials PhysicsMetallic MaterialsAlloysDopingElectrical ConductivityMetal MaterialsThermal Properties Of MaterialsThermoelectric MaterialsComposition Dependence Of PropertiesElectrical ResistivitySeebeck CoefficientTemperature DependenceTemperature Dependence Of Electrical PropertiesTemperature-dependent ResistivityThermal ConductivityThermoelectric Properties
We report on the temperature dependence of the electrical resistivity and the Seebeck coefficient for the p-type Fe2(V1-x-yTixTay)Al alloys with compositions 0≤x≤0.10 and 0≤y≤0.10, in addition to the composition dependence of the thermal conductivity at room temperature. While Fe2VAl (x=0, y=0) exhibits a semiconductor-like behavior in the electrical resistivity, a slight doping of Ti and Ta causes a significant decrease in the resistivity at low temperature and a large enhancement in the Seebeck coefficient, reaching 90 μV/K for x=0.03 and y=0.10. The power factor is found to be substantially larger than that for the p-type Fe2(V1-xTix)Al alloys so far reported. Although the thermal conductivity for Fe2(V1-xTix)Al remains in the range of 24∼28 W/mK for 0≤x≤0.10, it decreases significantly with the Ta substitution, reaching 11∼12 W/mK for 0≤x≤0.10 and y=0.10. We conclude that doping of heavier atoms such as Ta reduces more effectively the lattice thermal conductivity.
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