Electronic Transport Properties of Sn-doped CoSb3 Prepared by Encapsulated Induction Melting

Sn-doped CoSb
₃
skutterudites (CoSb
_3-y
-ySn
_y
) were prepared by encapsulated induction melting and their electronic transport properties were investigated. Carrier concentration increased with increasing the Sn doping content and the Sn dopant could affect the electronic structure of CoSb
₃
and generate excess charge carriers (holes). However, carrier mobility decreased with increasing the doping content, which indicates that the hole mean free path was reduced by the impurity scattering. Seebeck coefficient decreased with increasing the carrier concentration. Electrical resistivity slightly decreased with increasing the carrier concentration because the carrier mobility was reduced by the impurity scattering as the carrier concentration increased. The lattice thermal conductivity was dominant in the Sn-doped CoSb
₃
skutterudites. Seebeck coefficient showed a positive value at all temperatures examined and it increased as the temperature increased. Sn-doped CoSb
₃
lies on the semimetallic range which confirms a highly degenerate semiconductor.