Oxygen vacancies induced ferromagnetism in undoped and Cr doped SnO_2 nanowires

摘要

We presented detailed characterizations of the ferromagnetic properties of undoped and Cr-doped SnO_2 nanowires synthesized by chemical vapor deposition. All the samples exhibit room-temperature ferromagnetism. Our experiments reveal that, in addition to the contribution of surface oxygen vacancies, Cr doping into SnO_2 plays an important role in tuning the ferromagnetism of SnO_2 nanostructures. Doping the SnO_2 nanowires with 1.8at.% Cr enhances the magnetization by 28%. We applied the bound magnetic polaron model to successfully explain the enhancement of ferromagnetism.