Neutron diffraction study of the chiral magnet MnGe

Abstract

The magnetic structure of cubic MnGe has been determined by powder neutron diffraction. MnGe has a helical spin structure with a propagation vector $\mathbf{k}=(0,0,\ensuremath{\zeta}$), where $\ensuremath{\zeta}=0.107(5)$ just below the transition temperature ${T}_{N}=170$ K. The $\ensuremath{\zeta}$ value increases upon cooling and locks in to the value of 0.167(4) below 30 K. The moment value is 2.3(5)${\ensuremath{\mu}}_{B}$ at 2 K. The onset of the magnetic order is connected with a symmetry lowering from cubic to orthorhombic.