InSb:Mn - A high temperature ferromagnetic semiconductor

Diluted magnetic semiconductor InSb:Mn exhibits a ferromagnetic behavior up to T ∼ 600 K due to presence of nanosize MnSb precipitates [Kochura et al., J. Appl. Phys. 113, 083905 (2013)]. Transport properties of InSb:Mn, including the resistivity, the magnetoresistance (MR), and the Hall effect, are investigated between T ∼ 1.6 and 300 K in magnetic fields B up to 15 T. The resistivity, ρ(T), displays an upturn with lowering the temperature below T ∼ 10–20 K attributable to the Kondo effect, where the universal Kondo behavior is observed. The Hall resistivity, ρH, demonstrates a nonlinear dependence on B up to T ∼ 300 K, suggesting an anomalous contribution due to the effect of the MnSb nanoprecipitates. The relative MR, Δρ(B)/ρ(0), is positive (pMR) above T ∼ 10 K and transforms into a negative one (nMR) with lowering temperature. The Hall effect and pMR are interpreted simultaneously with the two-band model, addressed to presence of the two types of holes with quite different concentrations and mobilities. The dependences of nMR on B and T follow those of the Khosla–Fischer model, taking into account damping of the spin-dependent scattering of charge carriers in magnetic field.