The BFO Base Dmagnetoelectric Ceramic Materials Of Doping Modification Research

Multiferroics:the materials which cover several ferroic states, including at least two of the elastic order, electric order and magnetic order, simultaneously in the same phase. The ferroelectromagnet which has both electric order and magnetic order is a subsystem of multiferroics. By far, above the room temperature, BiFeO3may be the only material exhibiting ferroelectric property and magnetism at the same time, and it is a material having magnetoelectric effect which makes it a very potential application material. However, BiFeO3has these problems:preparation process is complicated, phase pure sample is hard to get, large leakage current and small magneto-electronic coupling effect.In this paper, single-phase BiFeO3, Bi1-xSmxFeO3(X＝0.02-0.2) and Bi9-xLaxTi3Fe5O27(x=1、2、3) ceramics were prepared using Bi2O3and Fe2O3as raw material and Sm2O3and La2O3as additives by improving solid-state reaction method and traditional solid-state reaction method separately. Conventional solid-state reaction method has many advantages in synthesis of ceramics, such as simple device, prepared material well mixed, easier composition control, and low cost. It is a common method in synthesis of ceramics.After many tests in ordinary stove, we prepared single-phase BiFeO3and Bi1-xSmxFeO3(x＝0.02-0.2) ceramics by improving solid-state reaction method. X Pert PRO x-ray diffraction instrument, which was made in Holland PANalytical Company, was used to research on microstructures. By which we found the better conditions to prepare a single-phase. The dielectric properties were measured by a precision impedance analyzer (Wayne Kerr,6500B) and the dielectric temperature curve was analyzed.At last, single-phase Bi9-xLaxTi3Fe5O27(x＝1、2、3) ceramics were successfully prepared by traditional solid-state reaction method. Through the microstructures and morphology analysis, we found that the ceramic structure of the sample did not change with increasing of La, but the La ions suppressed the grain growth. Dielectric, ferroelectric, ferromagnetic, optical properties of samples were measured and analyzed their results.