First-principles insight into the surface magnetism of Cu-doped SnO2 (110) thin film

Abstract

The electronic structures and magnetic properties of Cu-doped SnO₂ thin films with (110) surfaces have been investigated by density functional theory. The Cu dopants preferentially substitute at the five-fold coordinated, rather than six-coordinated, Sn sites at the (110) surface. The size of the magnetic moments depends on the sites occupied by Cu dopants in the thin film. A Zhang-Rice-like singlet is found when Cu is located at five-fold coordinated Sn site. The Cu-doped SnO₂ system exhibits half-metallic ferromagnetism. Robust ferromagnetic couplings between these local magnetic moments could be established on the Cu-doped SnO₂ (110) surface due to the delocalized O-2p holes.