Electron localization and spin-dependent transport property of CoNb 0.6Mn 0.4Sb half-Heusler alloy

The transport property of CoNb _0.6Mn _0.4Sb half-Heusler alloy has been investigated from 2 to 300 K in the presence of the magnetic field. It has been found that the temperature dependence of resistivity exhibits a semiconducting-like (SCL) behavior at low temperature (less than 50 K), while an up-then-down (UD) shape at temperature greater than 50 K. In the SCL range, the transport regime is well described by Mott localization law ρ=ρ₀× exp(T₀/>T)^p with p=1/4 than by an activation law. In the UD region, the resistivity is sensitive to the magnetic field, and the transport property is determined by spin-dependent scattering and electron localization.