Crystal Structure and Physical Properties of Skutterudites SrPd4Sn x Sb12-x

A Pd-based skutterudite phase SrPd4Sn (x) Sb12-x in which the 8c sites of the structure are occupied solely by Pd atoms and with a homogeneity range of 4.3(2) a parts per thousand currency sign x a parts per thousand currency sign 5.8(2) (wavelength dispersive x-ray spectroscopy) has been synthesized by solid-state reaction then spark-plasma sintering (SPS). It crystallizes as the filled-skutterudite structure type, electronically compensated by substitution of Sn for Sb at framework (24g) positions. The unit cell decreases substantially with increasing nominal and detected Sn content. Magnetization, specific heat, Hall effect, electrical resistivity, thermopower, and thermal conductivity were measured for the SPS-treated samples. SrPd4Sn (x) Sb12-x is a diamagnetic material. Depending on composition it occurs in the metallic or semiconducting states. Hall effect data show that the type and concentration of most of the carriers depend on the Sn/Sb atomic ratio. The thermal conductivity of SrPd4Sn (x) Sb12-x is approximately 3.0-5.0 W K-1 m(-1) at 300 K. The Seebeck coefficient is negative throughout the temperature range covered, reaching approximately -20 mu V K-1 at 300 K.