Preparation Process And Characteristic Investigation Of Core-Shell CoFe₂O₄/BaTiO₃Nanocomposites

Multiferroic composites consisting of two or more materials with ferroelectric, ferromagneticshow a magnetoelectric(ME) coupling effect due to the magnetically or electrically inducedmechanical deformation between two phases. These materials are attractive because they offer thepossibility to control the polarization by a magnetic field or the magnetization by an electric field.Many studies have adopted conventional ceramic processes to produce the composites by mixing andsintering CFO/BTO powders together. CFO and BTO epitaxial thin films have also been synthesizedand large ME effect have been observed.In this work, CFO nanoparticles were prepared by precursor thermal decomposition, andprepared CFO nanoparticle with different size from5nm-30nm. The core-shell BTO/CFOnanoparticls were prepared by sol-gel method and chemical co-precipitation. Futuremore,ferroelectric/ferrite composites of CFO/BTO ceramics were then synthesized. The dependence of theferroelectric and magnetic properties on the content of CFO has been investigated systematically.The CFO/BTO core-shell nanoparticls of multiferroic material prepared by sol-gel method andchemical co-precipitation had good magnetization properties. The size of the core-shell CFO/BTOnanoparticls were from50nm to100nm.No interface reaction was observed in the multiferroic ceramics and the samples have beenconfirmed with excellent ferroelectric and ferromagnetic properties. The ceramics with30%CFOsintered at1280℃for exhibit hign piezoelectric and magnetization properties: Ms=35emu/g, εr=750,Ps=1.2μC/cm2.