Conduction mechanisms and enhanced multiferroic properties of 2-2 type Bi0.89Sm0.11FeO3-NiFe2O4 composition thin films

摘要

Pure BiFeO3 (BFO), BiFeO3-NiFe2O4 (BFO-NFO) and Sm-doped Bi0.89Sm0.11FeO3-NiFe2O4 (BSFO-NFO) thin films were prepared on FTO/glass (SnO2:F) substrates via a sol gel method. The effects of NFO layer and Sm-doping on the crystalline structure, leakage current, ferroelecttic and ferromagnetic properties of all the thin films were investigated. Rietveld refinement of X-ray diffraction data indicated that BFO phase in BFO-NFO and BSFO-NFO films is trigonal with different space group of R3c:H and R3m:R. The leakage current of BFO film shows Ohmic emission at the entire electric field, whereas the dominant mechanism is changed to Fowler-Nordheim tunneling emission at the high electric field in the BFO-NFO and BSFO-NFO films. The improved ferroelectric and ferromagnetic properties have been observed in the BSFO-NFO film, e.g., large remanent polarization is 66.18 mu C/cm(2) and large saturation magnetization is 31.86 emu/cm(3). (C) 2014 Elsevier Ltd and Techna Group S.r.l. All rights reserved.