SYNTHESIS OF FILLED SKUTTERUDITE COMPOUND YBXCO4SB12 BY SOLID STATE MICROWAVE
The skutterudite semiconductor thermoelectric alloy YbxCo4Sb12 (x = 0.15- 0.3) was synthesized by solid-state microwave. The morphology of the micro/nanostructure and polycrystalline stoichiometric ratio of YbxCo4Sb12 (x =0.15- 0.3) were examined using scanning electron microcopy (SEM) and energy dispersive X-ray spectra (EDX). The structures of the skutterudite polycrystalline alloy YbxCo4Sb12 were examined by X-ray diffraction (XRD) patterns. A cubic structure was observed, and the lattice constant increased with increasing amount of Yb, with doping levels from x=0.15 to 0.3 and saturated with increments. The thermoelectric properties including electrical conductivity (σ), Seebeck coefficient (α) and electrical power factor)PF) were measured at a temperature range of 298–700 K. The transport properties of skutterudites alloy demonstrate a semiconductor behavior, during the temperature measurement, which indicated the change of electronic band structure. The Hall effect and Seebeck coefficient measurements have shown p-type conductivity in samples. The highest value of the Seebeck coefficient was 176.84 μV/K with doping levels x=0.3, at 329 K.
Keywords: Skutterudite semiconductor, YbxCo4Sb12, thermoelectric materials, thermoelectric properties, X-ray diffraction.