The Multiferroic Properties Of Bi Series Layered Perovskite

In a recent research, the multiferroic materials can be widely used in the new information storage devices, sensors and photoelectric materials and other fields, which has attracted widespread attention. In recent decades, multiferroic materials has been greatly developed because it can be applied to the miniaturization and integration of equipment. The Bi series of layered perovskite thin films as an important branch of ferroelectric materials has excellent ferroelectric, piezoelectric, leakage and other electrical properties. Moreover, Bi4Ti3O12 and Bi0.5(Na0.5K0.5)0.5TiO3 as its two important components have great application prospect and the environmental protection effect, which compared with PZT. For that reason, Bi4Ti3O12 and Bi0.5(Na0.5K0.5)0.5TiO3 films is obtained using chemical sol-gel method, which electronic properties and optical properties were researched. Through a series of characterization of electrical and optical properties found that ferroelectric domain of Bi0.5(Na0.5K0.5)0.5TiO3 could obtain good feature, which is good for its ferroelectric, leakage and fatigue properties. The Bi4Ti3O12 obtained excellent electrical properties by Zr element doped, which make the internal lattice distortion and distortion of the octahedron and effective regulate of the spectral response of the photovoltaic and make it happen the red shift phenomenon, and make the spectral response of photovoltaic moving the visible light range.Although excellent electrical properties and optical properties of ferroelectric thin film is obtained by element doping. Bi4Ti3O12 and Bi0.5(Na0.5K0.5)0.5TiO3 are performance of the single of ferroelectric materials, which don’t have multiferroic features. So we through sol-gel method preparation of three kinds of composite films, which are BiFeO3/Bi4Ti3O12 composite film, Bi4Ti3O12/Bi5Ti3FeO15s composite film and Bi4Ti3O12/Co2Fe2O4 composite film. The three kinds of composite film not only has excellent ferroelectric properties, leakage and piezoelectric properties, but they composite with the ferromagnetic materials making it obtained the ferromagnetic properties. This method making lead-free based ferroelectric thin film has the multiferroic properties, and obtain new properties magnetoelectric properties. The excellent coupling between piezoelectric phase and piezomagnetic phase obtain the three kinds of composite films, which have outstanding magnetoelectric output. Through the effective magnetoelectric coupling between layer and layer can make lead-free materials more widely used in magnetic memory, nonvolatile storage, random storage devices.