bifeo3基陶瓷的制备及多铁性分析word格式论文.docxVIP

AbstractIn recent years, Multiferroic materials, which show simultaneously ferroelectricity, ferromagnetism and/or even ferroelasticity, and the magnetoelectric coupling between the ferroic order parameters, have been in the forefront of materials research due to their interesting fundamental physics and potential applications in sensors, spintronics and information storage, etc. BiFeO3 is the only one that exhibits both ferroelectricity and G-type antiferromagnetism at room temperature, with a high Curie temperature(TC) of~1103K and Néel temperature (TN) of ~643K. But measurement of ferroelectricproperties in bismuth ferrite has been limited by leakage problems, due to low resistivity, defect, and non-stoichiometry issues in its bulk form. In addition, the weak magnetic also severely limits the actual application.This dissertation focuses on ions-doping modification and making composite with ferromagnetic material to enhance the multiferroic properties and the magnetoelectric coupling of BiFeO3 ceramic at room temperature and studying the physical mechanisms underlying in the enhancement. The main research work is listed as follows:The Bi1-xBaxFeO3(x=0, 0.05, 0.1, 0.15, 0.2, 0.25) nanoparticles were prepared by a modified sol-gel method followed by a rapid quenching process we report the synthesis and study of crystal structure, electric and magnetic properties of nanocrystalline multiferroic system. When x=0.15, the BBFO ceramic showed a pure phase of polycrystalline perovskite structure and exhibited the best ferroelectric property with the largest remanent polarization. with the increasing of doping content, the magnetic characteristics of the doped ceramics was improved.The Bi1-xBaxFeO3(x=0, 0.1, 0.15, 0.2, 0.25) ceramics was prepared by mechanical ball-milling followed by a rapid quenching process. We study the effect of differentdoping content on the crystal Structures Phase，microstructure，magnetic and electricalproperties of BBFO, The possible reas