Orbital magnetic moments of oxygen and chromium in CrO2

Abstract

With measurements of the magnetic circular dichroism and band-structure calculations in the local spin density approximation (LSDA+U) approach, we revealed that the orbital moment of O in CrO2 is ferromagnetically coupled to that of Cr, whereas the spin moment of O is antiferromagnetically coupled to that of Cr. Spin and orbital magnetic moments of Cr and O are enhanced as Coulomb interaction energy U increases. Comparing the magnetic circular diachromism data with the LSDA+U calculations, we conclude that it is essential to include the on-site Coulomb energy for adequately describing the orbital magnetic moments of CrO2.