Skutterudite structure and thermoelectric property in thePr-Fe-Ni-Sb system

M. Hasaka¹, T. Morimura², S. Tabata²

¹Department of Materials Scienceand Engineering, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521,Japan

²Graduate School of Science andTechnology, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521, Japan

Skuteruditesor filled skutterudites are promising thermoelectric materials for energyconversion, because of the high carrier mobility and low heat conductivity. Inthis paper, filled skutterudite structure and thermoelectric property in thePr-Fe-Ni-Sb system with the compositions of Pr:Fe:Ni:Sb=f:8-x:x:24 wereinvestigated by means of X-ray diffraction experiment, transmission electronmicroscopic observation, energy dispersive x-ray analysis and measurement ofSeebeck coefficients. The skutterudite structure coexisted with the otherstructures when valance electron total number is large or small. The fillingfraction of Pr in void sites increases with decreasing Ni concentrationparameter x. The lattice parameter, lattice coordinates of Sb and Seebeckcoefficient depended on f and x. The polarity of the filled skutteruditechanges with the valance electron total number per a unit volume.