Room-temperature ferromagnetism in CrSi2(core)/SiO2(shell) semiconducting nanocables

Abstract

Room-temperature ferromagnetism has been observed in high density free-standing CrSi2(core)/SiO2(shell) semiconducting nanocables, which is contrast to diamagnetic properties of both CrSi2 and SiO2 in bulk. The hexagonal CrSi2 C40-type nanowires, sheathed with a thin amorphous SiO2 layer, grow along [0001] direction. The results of first-principles simulations indicate that Cr atoms around the interface are with anomalously high magnetization (about 2 μB/atom), due to distorted/dangling bonds and surrounded oxygen atoms. Evaluations can be very consistent with measurements by further considering the effects of interfacial roughness and more distribution of oxygen around the interface. These results point toward a different way to tune nanomagnetism in core/shell nanowires.