Magnetic, electronic, and transport properties of the high-pressure-synthesized chiral magnets Mn1-xRhxGe

Abstract

We report on the structural, magnetic, and transport properties of a set of high-pressure-synthesized compounds Mn1-xRhxGe (0≤x≤1) with chiral magnetic ordering. The magnetic and transport properties depend substantially on the concentration of rhodium (x) and the pressure. The saturation magnetic moment corresponds to a known high-spin value for pristine MnGe (x=0) and decreases almost linearly with increasing concentration x. In addition, x-ray magnetic circular dichroism spectra taken at 10 K and 2 T indicate magnetic polarization of the Rh 4d electron states and Ge 4p states, which decreases with x, too. In rhodium-rich compounds (x≥0.5), the temperature of the magnetic ordering increases significantly with pressure, whereas in manganese-rich compounds (x<0.5) the temperature decreases. Three different tendencies are also found for several structural and transport properties. In the intermediate range (0.3≤x≤0.7), samples are semiconducting in the paramagnetic phase, but they become metallic in the magnetically ordered state. We carried out ab initio density-functional calculations of Mn1-xRhxGe at various concentrations x and traced the evolution of the electronic and magnetic properties. The calculation results are in good agreement with the measured magnetic moments and qualitatively explain the observed trends in transport properties. © 2018 American Physical Society.