Effect of growth temperature on ferromagnetism in Mn:TiO_2 thin film grown on SrTiO_3:Nb substrate

摘要

We investigate the relationship between growth temperature and ferromagnetism in Mn:TiO_2 thin film grown on SrTiO_3:Nb substrate by plasma-assisted molecular beam epitaxy. The samples show different surface morphology, crystal quality and magnetic behavior with different growth temperature. It is concluded that the oxygen vacancies generated in the Mn:TiO_2 thin film, together with the ones diffused from SrTiO_3:Nb substrate, localize at the thin film/substrate interface during high-temperature growth, accounting for the more remarkable room-temperature ferromagnetism.