Magnetoelectric coupling in NiFe2 O4-BiFeO3 composite films

Abstract

Multiferroic xNFO-(1-x)BFO (x =0.00 0.10, 0.15, 0.20, 0.25) composite films are prepared through self-assembling growth on Au/Ti/SiO2/Si substrates by chemical solution deposition (CSD). X-ray diffraction analysis shows that the perovskite BiFeO3 and the spinel structured NiFe2O4 phases are formed and separated. The leakage current density (J) in the film decreases and the remnant polarizations (M r) increases with the introduction of NFO. The value of J in 0.25NFO—0.75BFO film is found to be nearly two orders of magnitude lower than that in the BFO film, and the M r and the saturation magnetization ( M s) reach maxima, i.e. 2.3μC/cm2 and 70.2 kA·m-1, respectively. Therefore, from the calculation for magnetic moment of NFO we can conjecture that magnetoelectric coupling exists in the composite films.