1995 年 7 巻 3-4 号 p. 168-173
Iron disilici de FeSi2 is the most hopeful Thermoelectric Semiconductor, because both the components Fe and Si are deposited in plenty, the thermoelectric properties of FeSi2 devices can readily be designed by controlled doping, and so on. Sintered bodies of Fe1-xMnxSi2 (0≤x≤0.10) and Fe1-yCoySi2 (0≤y≤0.10) were prepared by the ceramic techniques, which are suitable for mass-production, and the roasting, sintering and annealing conditions in the sintering were investigated. For completely semiconducting specimens, the resistivity ρ and thermoelectric power Q were measured in the temperature range from 100 to 1400K in an argon atmosphere. The electrical resistivity ρ of Fe1-xMnxSi2 (x=0.03 and x=0.06) indicated the relationship ρ=ρoexp[(Ea+Eh)/(kT)] in the temperature range from 150 to 600K, where Ea and Eh are the activation energy of the acceptor and the hopping energy, respectively. The Hall mobility μH showed the relationship μH=μoexp[-Eh/(kT)] in the temperature range from 150 to 250K. The electrical conduction mechanism of Fe1-xMnxSi2 is qualitatively explained on the basis of the small polaron model.