Strong modulation of magnetism in multiferroic CoFe2O4/0.7 Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 oxide composite films

Multiferroic magnetoelectric composite films have been becoming the research focus as the candidates for sensors, memories, spintronics and microwave devices. Compared to ferroelectric single crystal consisting of the heterostructure, the functional composite film realizes the magnetism control under only a few volts which brings the advantage of safety and low energy consumption in the memory devices. Here, the CoFe2O4/0.7PbMg1/3Nb2/3O3-0.3PbTiO3 oxide composite thin films were deposited on SrRuO3-buffered SrTiO3 substrate by pulsed laser deposition method. The structural, ferroelectric, magnetic and magnetoelectric properties have been studied respectively. The polarization reversibility of ferroelectric domain was investigated in the PMN-PT films by piezoresponse force microscopy. The coercive field of the CoFe2O4 film ranges from 900 Oe to 975 Oe under the applied direct current voltage. By performing the alternative current voltage modulated magneto-optical Kerr effect test, the dominating coupling mechanism in the composite films influenced by the CoFe2O4 film thickness was discussed. Our study indicates the potential application of electric field assisted magnetic data storage device.