Study On Magnetoelectric Coupling Effect In NiFe/PIN-PMN-PT Multiferroic Heterostructures

Multiferroic composites has wide application prospect in new magnetoelectric storage and spintronics devices owing to the coupling effects between different ferroic orders,and it has been a hot research direction recently.Compared to Pb(Mg_1/3Nb_2/3)O₃-Pb Ti O₃?PMN-PT?and Pb(Zn_1/3Nb_2/3)O₃-Pb Ti O₃?PZN-PT?single crystals,Pb(In_1/2Nb_1/2)O₃-Pb(Mg_1/3Nb_2/3)O₃-Pb Ti O₃?PIN-PMN-PT?single crystal has higher coercive field and phase transition temperature.The magnetoelectric coupling effect in Ni Fe/PIN-PMN-PT heterostructures was chosen as the topic of this study.Firstly,the multiferroic heterostructures were prepared by DC magnetron sputtering.Electric-field control of ferromagnetic resonance is becoming a popular method to study the magnetoelectric coupling effect in multiferroic heterostructures in recent years.This method was adopted and ferromagnetic resonance was controlled by electric field in the samples.The ferromagnetic resonance test system based on S-shape co-plane waveguide can work in frequency-sweep mode or field-sweep mode.The resonance frequency in[100]direction increases as the electric field intensity increases,and the resonance magnetic field decreases.The resonance frequency in[01 1]direction decreases as the electric field intensity increases,and the resonance magnetic field increases.The result corresponds with the experimental results in orther reported papers.Secondly,the experiment result was analyzed using effective-magnetic-field theory.The changing values of effective magnetic field calculated from experiment and equation respectively are close to each other,so the magnetoelectric coupling effect derives from the strain across the FM/FE interface.The anisotropy of in-plane effective magnetic field leads to the different electric-field control of ferromagnetic resonance in[100]and[01 1]directions.The converse magnetoelectric coupling coefficient was calculated by the changing value of effective magnetic field.At last,NiFe/PIN-PMN-PT multiferroic heterostructures model was built and simulated using COMSOL Multiphysics software.The magnetization of the ferromagnetic film changes when the external electric field is applied.Electric-field control of magnetism is realized in the model and in-plane magnetization anisotropy appears under electric field.Since there is few reports on the simulation of electric-field control of magnetism using COMSOL,this work is creative relatively.The simulating result corresponds well with the experimental result.The magnetoelectric coupling effect of Ni Fe/PIN-PMN-PT multiferroic heterostructures was studied deeply in this dissertation.The magnetoelectric coupling property is very good,and the multiferroic heterostructures has good application prospect in electrically tunable microwave magnetic devices.