Thermoelectric properties and electronic structure of Sn-doped CoSb3

Electron transport properties of Sn-doped CoSb₃ skutterudites were studied by electrical resistivity, thermopower, Hall effect and thermal conductivity measurements. The crystal structure of powder samples was analyzed by the Rietveld refinements of X-ray diffraction data. ¹¹⁹Sn Mossbauer technique was used for investigations of Sn atom distributions. It was shown that the obtained spectra could be fitted by two sets of hyperfine parameters related to different Sn positions. Electronic structure of both ordered compounds (Co₄Sb₁₂, Co₄Sb₁₁Sn and SnCo₄Sb₁₂) and disordered alloys (Co₄Sb_12-xSn_x and Sn_yCo₄Sb₁₂) were calculated by the charge self-consistent KKR-CPA methods. This approach allowed determining density of states (DOS) of impurities placed in the semiconducting CoSb₃.