Electronic structure and x-ray magnetic circular dichroism in the Mn₃CuN perovskite

Abstract

The electronic and magnetic structures of Mn₃CuN are investigated theoretically from first principles using the fully relativistic Dirac LMTO band structure method. Mn₃CuN possesses a magnetic phase transition at TC = 143 K from a high temperature paramagnetic phase to a low temperature ferromagnetic one with a noncollinear magnetic structure. The transition is accompanied by a structural change from the cubic to the tetragonal lattice. In low temperature phase two Cu moments and two Mn moments (Mn₂ and Mn₃) ferromagnetically align along the c axis while other four Mn1 magnetic moments are canted from the c axis to [111] direction by angle Q= ±76.2. The x-ray absorption spectra and x-ray magnetic circular dichroism (XMCD) spectra of Mn₃CuN are investigated theoretically from first principles. The origin of the XMCD spectra in the Mn₃CuN compound is examined. The calculated results are compared with the experimental data.