Thermoelectric properties of YbxCo4Sb12 prepared under high pressure

Abstract

We report the thermoelectric properties of partially filled skutterudites YbxCo4Sb12 synthesized under high pressure. The phase compositions and actual Yb filling ratios were characterized by X-ray diffraction and electron probe microanalysis (EPMA), respectively. The EPMA results show that the maximum actual Yb doping content can be increased to 0.29, the highest for any YbxCo4Sb12 reported so far. The lattice thermal conductivity is reduced by increasing the Yb filling fraction. The minimum value is 2.02 W m−1 K−1 for Yb0.6Co4Sb12 at 300 K. The electrical conductivity and the Seebeck coefficient for Yb-doped samples exhibit the typical behavior of n-type filled skutterudites. The maximum ZT value is 0.1 for Yb0.2Co4Sb12 at room temperature.