The unusual magnetic properties are observed in oxygen deficient BaTiO3-δ(BTO) and Nb:BaTiO3-δ(BNTO) thin films fabricated on SrTiO3 substrates by laser molecular beam epitaxy.The distinct magnetic hysteresis loops are observed in the oxygen deficient BTO and BNTO thin films in a temperature range of 5 to 300 K,whereas the diamagnetism is observed in both BTO and BNTO annealed at 1 atm of oxygen.The dopant Nb only enhances the magnetization in BNTO thin films,but has little effect on the coercivity.The magnetism of BTO and BNTO films is proposed to be the oxygen vacancies by origin.
YANG Fang,JIN KuiJuan,LU HuiBin,HE Meng,WANG Cong,WEN Juan & YANG GuoZhen Beijing National Laboratory for Condensed Matter Physics,Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China