The Research Of Preparation And Properties About Some Multiferroic Composite Materials

In recent years, multiferroic materials with coexistence of at least two ferroic orders (ferroelectric, ferromagnetic, or ferroelastic) have drawn increasing interest due to their potential for applications as multifunctional devices. The multiferroic materials including the single phase multiferroic materials and the composite multiferroic materials. The composite multiferroic materials is well and widely studied in film and bulk form, due to its unique advantage.In this paper, 1-xBi0.85La0.15FeO3-xCoFe2O4, 0.8Bi1-xLaxFeO3-0.2CoFe2O4, 0.55Bi1-x LaxFeO3-0.45CoFe2O4, 1-xBi0.8La0.2FeO3-xCuFe2O4, 0.9Bi1-xLaxFeO3-0.1CuFe2O4, 1-xBi0.8La0.2FeO3-xZn0.6Mn0.4Fe2O4 were prepared by the conventional solid state reaction. It’s also investigated the properties of the composition systems, such as the structures, magnetic, dielectric and the ferroelectric.For the 1-xBi0.85La0.15FeO3-xCoFe2O4, 1-xBi0.8La0.2FeO3-xCuFe2O4å'Œ1-xBi0.8La0.2 FeO3-xZn0.6Mn0.4Fe2O4 samples, no third phases can be detected, which indicated that no any chemical reaction had taken place between two phases. The intensity of ferroic peaks and the magnetic properties enhanced with its increasing percentage in the composition. For the 1-xBi0.85La0.15FeO3-xCoFe2O4 samples with x=0.1, well saturated P-E loop can be obtained. The saturated polarization (Ps) and remnant polarization (Pr) are better than the single phase Bi0.8La0.2FeO3. Howerver, the dielectric constantεwas decreasing with the increasing of x. For the M-T loops of the 1-xBi0.8La0.2FeO3-xCuFe2O4 samples, two magnetic transition at T=150K and T=250K were identified, which was in accordance with the property of the single phase Bi0.8La0.2FeO3 and CuFe2O4. For the 1-xBi0.8La0.2FeO3-xZn0.6Mn0.4Fe2O4 samples, the dielectric constantεwas increasing with the increasing of x. Compared with the T=300K, the magnetic property was better at T=10K.For the 0.8Bi1-xLaxFeO3-0.2CoFe2O4, 0.55Bi1-xLaxFeO3-0.45CoFe2O4 and 0.9Bi1-x LaxFeO3-0.1CuFe2O4 composition samples, there was no any chemical reaction had taken place between the two phases. There was a structural phase transition near x=0.3. The magnetic property was enhanced with the increasing of x. The dielectric constant increases firstly with the La content increasing and then decreases with x=0.3. The 0.8Bi1-xLaxFeO3-0.2 CoFe2O4 samples had a higherεthan 0.55Bi1-xLaxFeO3-0.45CoFe2O4.