Magnetic and magnetotransport properties of MnSb polycrystals near equatomic composition

In this work, we studied properties of the MnSb polycrystalline samples synthesized from a melt of high-purity elements. We observed the presence of a ferromagnetic state with Curie temperature significantly higher than room temperature (Tc≈568 K). The results of structural and magnetic studies suggest the presence of a slight deviation from the equatomic composition towards the small excess of Mn (∼ 1 at.%). It was found that the studied sample have high resistivity (up to 425 μΩ⋅cm) at room temperature, however, it significantly decreases upon cooling, breaking the Mooij correlation. The magnetoresistance of the MnSb polycrystal is positive at low temperatures and does not get saturated in studied magnetic field range (≤40 kOe), which suggests that this contribution stems from the classical Lorenz mechanism. Negative magnetoresistance contribution, associated with the suppression of thermal spin fluctuations by external magnetic field, becomes dominant at higher temperatures (T≥74 K). The normal Hall effect coefficient is positive and significantly increases upon heating, which indicates a substantial variation of delocalized holes density with temperature. The anomalous Hall effect coefficient is also positive, and its temperature dependence suggests that the skew scattering mechanism provides a considerable contribution at low temperatures.