Enhanced d0 ferromagnetism via carbon doping in rare-earth sesquioxides: DFT prediction

Abstract

In this study, a new possible diluted magnetic semiconductor (DMS) with d0 ferromagnetism was predicted. RE2O3 compounds (RE = Sc, Y, and Lu) doped with a nonmagnetic impurity (carbon) are investigated using density functional theory. It was found that Sc2O2.875C0.125 and Lu2O2.875C0.125 are similar to the recently predicted room-temperature DMS in Y2O2.875C0.125 [Phys. Rev. B 97, 184,411 (2018)]; while, both show an enhanced Curie temperature. An RKKY-like interaction with indirect exchange interaction is assumed to induce ferromagnetic coupling in these materials. The calculations in this work also suggest that the Lu2O2.875C0.125 compound has an extended magnetism compared to other studied compounds because the carbon-cluster configuration (case 1) is less favorable. The findings of this study suggest that carbon-doped Lu2O3 would be the best candidate for spintronic devices.