Electronic transport properties of p-type CoSb3

The electronic transport properties were investigated on polycrystalline p-type CoSb₃ with different grain sizes (about 3 and 3×10² μm) to clarify the important factors which affect the hole mobility. The magnetic susceptibility was also measured. Samples were found to be stoichiometric and homogeneous without any segregation of other phases. From the temperature dependence of the hole mobility, it was found that the predominant scattering mechanism depends significantly on grain size. The magnetic susceptibility was found to be diamagnetic independently of grain size, and to depend weakly on the temperature. The susceptibility can be explained by taking into account the three contributions due to ion cores, conduction electrons, and residual magnetic impurities. From the analysis of the susceptibility, the effects of residual magnetic impurities on the transport properties were found to be negligible. In addition, the band gap energy of CoSb₃ was determined to be about 70-80 meV. The grain size is one of the key factors determining the transport properties of polycrystalline p-type CoSb₃