Synthesis and electronic transport properties of InzCo4Sb12-yTey skutterudites

InzCo4Sb12-yTey skutterudites were prepared by encapsulated induction melting, and their electronic transport properties were investigated. Single phase d-CoSb3 was obtained successfully by encapsulated induction melting and subsequent heat treatment at 823 K for 5 days. The Te atoms acted as electron donors by substituting for Sb atoms. The Hall coefficient and the Seebeck coefficient showed negative values, which confirmed the InzCo4Sb12-yTey skutterudites are n-type semiconductors. The electronic transport properties were affected greatly by Te doping rather than by In filling. The carrier concentration ranged from 7 x 10(19) to 4 x 10(20) cm(-3), and carrier mobility was 2 to 22 cm(2)/Vs. The Seebeck coefficient was increased and the electrical resistivity was decreased by Te doping and In filling. The thermal conductivity was reduced considerably by doping and filling due to phonon scattering, which is responsible for the decrease in lattice thermal conductivity.