First Principles Study Of Electronic Structure And Magnetic Properties Of Doping BiFeO₃

Multiferroic materials is a kind of material with multifunctional physical properties,which can show feiroelectricity and ferromagnetism at the same time under certain conditions.With the help of the magnetoelectric coupling effect,the electric field can be used to control the magnetic field in the material,which in turn the electric field in the material can also be controlled with the magnetic field,and these excellent properties making multiferroic materials have great potential applications in the electronic functional devices.BiFeO3 is perhaps the only multiferroic material with a high ferroelectric Curie temperature and a high anti-ferromagnetic Neel temperature above the room temperature.However,because of its internal magnetic spin spiral structure,which make the magnetism of BiFeO3 become smaller and greatly limit its applications.In this paper,based on the research status of BiFeO3,we studied the electronic structure and magnetic properties of BiFeO3 in different doping condition with the help of the first principle calculations,and the research content is as follows:1?Using the F ion replace the Fe ion in the BiFeO3,and study the effect of doping positon and doping concentration of F ions on the electronic structure and magnetic properties of BiFeO3.2?Anionic ion and cationic ion codoping the BiFeO3:(1)Using the F ion and alkaline earth metal ion codoping the BiFeO3,with F ion replacing the O ion and Ca ion substituting the Bi ion in A site,and study the effect of F ion and Ca ion codoping on the electronic structure and magnetic properties of BiFeO3;(2)Using the F ion and rare earth ion codoping the BiFeO3,with F ion replacing the O ion and the rare earth La ion substituting the Bi ion in A site,and study the effect of F ion and La ion codoping on the electronic structure and magnetic properties of BiFeO3;(3)Using the F ion and the 3d transition metal ion codoping the BiFeO3,with F ion replacing the O ion and the transition metal Co ion substituting the Fe ion in B site,and study the effect of F ion and Co ion codoping on the electronic structure and magnetic properties of BiFeO3;.3?Simulating the electron energy-loss spectroscopy of ZnFe2O4 in different inverse degree with the first principle calculations,and study the electronic structure,magnetic properties and the corresponding electron energy-loss spectroscopy of ZnFe2O4.In the last,we give the standard criterion for the electron energy-loss spectroscopy of ZnFe2O4 in different inverse degree.