Defect engineered d~0 ferromagnetism in tin-doped indium oxide nanostructures and nanocrystalline thin-films

摘要

Origin of unexpected defect engineered room-temperature ferromagnetism observed in tin-doped indium oxide (ITO) nanostructures (Nanowires, Nano-combs) and nanocrystalline thin films fabricated by pulsed laser deposition has been investigated. It is found that the ITO nanostructures prepared under argon environment exhibit strongest ferromagnetic signature as compared to that nanocrystalline thin films grown at oxygen. The evidence of singly ionized oxygen vacancy (V_0~+) defects, obtained from various spectroscopic measurements, suggests that such V_0~+ defects are mainly responsible for the intrinsic ferromagnetic ordering. The exchange interaction of the defects provides extensive opportunity to tune the room-temperature d~0 ferromagnetism and optical properties of ITOs.