The Magnetic Symmetry of α-Mn and the Parasitic Ferromagnetism from Magnetic Torque Measurements

Abstract

Magnetic torque measurements on α-Mn were performed as a function of applied magnetic field in the range H<12 kOe for temperatures 4.2°K≤T<T_N=95°K. The principal axis of the magnetic symmetry was determined to be along one of the ⟨100⟩ rather than the ⟨111⟩ in the temperature range 45°K≤T<T_N. At temperatures below 42.5°K a weak ferromagnetic component appeared in the torque curves. This ferromagnetic component corresponds to the parasitic ferromagnetism observed by Arrott et al.. It was found that this magnetism was not intrinsic, but is due to a small amount of Mn₃O₄ impurity.