Multiferroic BiFe1-xTMxO3/NiFe2O4 (TM = Mn, Cr) thin films: Structural, electrical and magnetic properties

Pure BiFeO3 (BFO), BiFeO3/NiFe2O4 (BFO/NFO), BiFe0.94Mn0.04O3/NiFe2O4 (BFMO/NFO) and BiFe0.94Mn0.04Cr0.02O3/NiFe2O4 (BFMCO/NFO) thin films were successfully prepared on FTO/glass (SnO2: F) substrates by sol-gel method. The results of structural analysis indicate that a propensity of the structure to undergo significant structural distortion from rhombohedral to tetragonal phase upon BFMO/NFO and BFMCO/NFO thin films. And the BFMO layer in the BFMO/NFO structure is in a relatively higher strain state compared with the other thin films. The BFMCO/NFO thin film shows the lowest leakage current density. Moreover, the better ferroelectric property with the remnant polarization of P-r = 84 mu C/cm(2) is observed in the BFMO/NFO thin film, which can be attributed to the movement of domains and domain walls of BFMO/NFO thin film is easier in BFMO layer than that of the BFMCO/NFO thin film in BFMCO layer. However, the highest saturation magnetization value of M-s = 27.22 emu/cm(3) is observed in the BFMCO/NFO thin film. The results suggest that ion-doping and NFO layer is an effective way to improve the electric and magnetic properties of the BFO/NFO thin films. (C) 2015 Elsevier B.V. All rights reserved.