First-principles calculation of the orbital magnetic moment of O and Cr in half-metallic CrO2

The electronic and magnetic properties of half-metallic CrO2 have been studied by using the full-potential linearized muffin-tin orbital method within the local spin-density approximation (LSDA)+U approach. It is found that the orbital magnetic moment of Cr atom is quenched while O atom exhibit relatively significant orbital moment in CrO2. For the Hubbard U of 3 eV, LSDA+U gives the orbital moment of -0.051mu(B)/atom for Cr and -0.0025mu(B)/atom for O, being in good agreement with the experimental orbital moments of -0.05 for Cr and -0.003mu(B)/atom for O, respectively. In contrast, LSDA gives the orbital moment of -0.037 for Cr and -0.0011mu(B)/atom for O, being too small as compared with the magnetic circular dichroism measurements. For the larger U considered in this work, both spin and orbital moments almost increase linearly with respect to U.