Crystal growth and magnetic structure of MnBi2Te4

Millimeter-sized MnBi$_2$Te$_4$ single crystals are grown out of Bi-Te flux\nand characterized by measuring magnetic and transport properties, scanning\ntunneling microscope (STM) and spectroscopy (STS). The magnetic structure of\nMnBi$_2$Te$_4$ below T$_N$ is determined by powder and single crystal neutron\ndiffraction measurements. Below T$_N$=24\\,K, Mn$^{2+}$ moments order\nferromagnetically in the \\textit{ab} plane but antiferromagnetically along the\ncrystallographic \\textit{c} axis. The ordered moment is 4.04(13) $\\mu_{B}$/Mn\nat 10\\,K and aligned along the crystallographic \\textit{c}-axis. The electrical\nresistivity drops upon cooling across T$_N$ or when going across the\nmetamagnetic transition in increasing fields below T$_N$. A critical scattering\neffect was observed in the vicinity of T$_N$ in the temperature dependence of\nthermal conductivity. However, A linear temperature dependence was observed for\nthermopower in the temperature range 2K-300K without any anomaly around T$_N$.\nThese indicate that the magnetic order in Mn-Te layer has negligible effect on\nthe electronic band structure, which makes possible the realization of proposed\ntopological properties in MnBi$_2$Te$_4$ after fine tuning of the electronic\nband structure.\n