Multiferroic Ferrite Bismuth Materials And Performance

Multiferroics are multifunctional materials which exhibits coexistence of ferroelec-tricity(or untiferroelectricity) , ferromagnetism(or antiferromagnetism) and ferroelas-ticity (or ferroelasticity) because of continuous series of fabric parameter. As a typical single-phase multiferroic,Bismuth ferrite (BiFeO₃) of perovskite structure has attracted renewed and ever increasing research interest during the past several years. which likely could be widely applied to such as Filter ,Sensor, Performor, Executor, Informationstorage and Non-linear optical hardware.The major work in this dissertation is to do research on BiFeO₃ by introducing several different synthesis methods,which includes the following three parts:1. Nanocrystalline BiFeO₃ powder was synthesized by a gel-combustion technique. This method is a new, simple and easy way for preparation of single phase BiFeO₃, and is very convenient for investigating and improving of the properties of BiFeO₃.The phase transition characteristics, structure, surface morphology, micromagnetism and macromagnetism are investigated by TG/DTA, XRD ,SEM and VSM repectively.2. For Bi_1-xBa_xFeO₃, when x is smaller than 0.2, it has a rhombohedrally perovskite structure. With Ba doping the structure of BiFeO₃ should be distorted, then the bond angle of Fe³⁺-O-Fe³⁺ and Fe⁴⁺-O-Fe³⁺ may be changed, this change in the bond angle results in the magnetization of Bi_1-xBa_xFeO₃.3. Working is done to probe the aggradation of Bismuth ferric oxide (BiFeO₃) thin film on the ITO-coated glass by electro deposition method. The effects of different electro deposition conditions on the microstructures of BiFeO₃ thin films were investigated simply。The results show that electro deposition method allows to synthesis BiFeO₃ films but the technic condition needs to be improved to reduce the impurity of Bi₂O₃ and Bi₂Fe₄O₉...