Physical Properties of Half-Heusler Antiferromagnet MnPtSn Single Crystal**Supported by the National Key R&D Program of China (Grant Nos. 2018YFE0202600, 2016YFA0300504), the National Natural Science Foundation of China (Nos. 11574394, 11774423, 11822412), the Fundamental Research Funds for the Central Universities, the Research Funds of Renmin University of China (RUC) (Nos. 15XNLQ07, 18XNLG14, 19XNLG17), and the Office of Basic Energy Sciences, Materials

Abstract

We report the growth of ternary half-Heusler MnPtSn single crystals and detailed study on its structural and physical properties. MnPtSn single crystal has a larger lattice parameter than that in polycrystal and it exhibits antiferromagnetism with transition temperature TN at about 215 K, distinctly different from the ferromagnetism of MnPtSn polycrystal. Hall resistivity measurement indicates that the dominant carriers are hole-type and the nearly temperature-independent carrier concentration reaches about 2.86 × 1022 cm−3 at 5 K. Moreover, the carrier mobility is also rather low (4.7 cm2⋅V−1s−1 at 5 K). The above results strongly suggest that the significant Mn/Sn anti-site defects, i.e., the content of Mn in MnPtSn single crystal, play a vital role on structural, magnetic and transport properties.