Study On Preparation And Properties Of CFO/PMN-PT Composite Films

Ferroelectric0.68Pb(Mg1/3Nb2/3)O3-0.32PbTiO3(PMN-PT) and ferromagneticCoFe2O4(CFO) thin films have been produced separately by sol-gel method ondifferent substrates, which were followed by the preparation of CFO/PMN-PTcomposite thin film. The effect of process condition and substrate on the textureand property of single phase PMN-PT thin film and CFO/PMN-PT composite thinfilm have been studied.Transpatent and stable PMN-PT sol was acquired by changing the preparationprocess of the precursor.Perovskite phase PMN-PT thin film was prepared by15%excessive lead with the anneal temperature of650C for two minutes. Different(100) and (111) textures of PMN-PT thin films were synthesized by the pyrolysistemperature of450C on Si(111)/SiO2/Ti/Pt(111) substrates of different Pt(111)crystallinity. The result shows that both them have well ferroelectric properties.Under the applied electric field of500kV/cm, the remanent polarization andcoercive field of PMN-PT thin film with (100) texture are35.3μC/cm2�'�170.4kV/cm respectively, which is higher than that of (111) texture.MgO(100)、LaAlO3(100) and SrTiO3(100) substrates have been used to preparePMN-PT thin film with high (100) texture. The mechanism on the (100) orientationof PMN-PT thin film was analyzed briefly. The result of ferroelectric property testshows that the remanent polarization increases and the coercive field reduces byenhancing the ratio of I(100)/I(110).PMN-PT/CFO type and CFO/PMN-PT type magnetoelectricity composite thinfilms have been assembled on Si(111)/SiO2/Ti/Pt(111) substrates, which exerts (100)texture and (111) texture respectively. The PMN-PT/CFO composite thin filmpossesses the remanent polarization of36.6μC/cm2and the coercive field of77.9kV/cm which shows better ferroelectric properties.CFO/PMN-PT composite thin films with different recombination mode wereprepared on the substrates of LAO(100) and STO(100). The research shows that theI(100)/I(110) of thin films enlarges along with the increase of the thickness of thebottomed PMN-PT thin films. The ferromagnetic properties of composite filmschange with the structure of composite films.