The Electronic Structures and Magnetic Properties of Un-doped In2O3: the First-Principle Calculation

The electronic structures and magnetic properties of native defects in cubic In2O3 are investigated systematically by the LDA + U first-principle calculations based on the density functional theory. It is found that the In2O3 system is a strongly correlated electron system; therefore, the coulomb potential of In-4d and O-2p should be considered. In this paper, the coulomb potential corrections are U In−4d=3 eV and U O−2p=5 eV. The magnetic moments of O interstitial, In vacancy, and In interstitial are 2 u B , 3 u B , and 1 u B , respectively, which are consistent with the analysis of group theory and molecular orbital theory. Moreover, the distributions of these magnetic moments are both local and extended. The magnetic couplings of O interstitials, In vacancies, and In interstitials are ferromagnetic, anti-ferromagnetic, and paramagnetic respectively, which are determined by electronic structures of defects. The formation energy of O interstitial is high, while that of the O Frenkel defect (that is the O interstitial-vacancy) is −4.98 eV. These results could provide the practical understanding to the room-temperature ferromagnetism in un-doped In2O3 system.