| Most common FeAl soft magnetic films were prepared by molecular beam epitaxy(MBE),and physical properties including static and dynamic magnetic properties of the films were investigated under electric field.The main research contents and experimental results are as following:First,an Fe/Al bilayer was prepared in this dissertation using molecular beam epitaxy(MBE)at room temperature and the impact of annealing on the magnetic properties of the film was investigated together with the interfacial chemical state and heterostructures of the Fe/Al bilayer structures.The experimental results demonstrated that the Fe/Al bilayer material system exhibited an atomically sharp interface and was thermally stable to a temperature of 150 °C.To the best of our knowledge,preparing an atomically sharp metal-metal heterostructure of Fe/Al bilayer has yet to be reported and the thermal stability of the interface in the fabricated Fe/Al bilayer is of the utmost importance in fundamental studies and potential applications.Second,a stable,tunable and non-volatile converse magnetoelectric effect(ME)in a new type of FeAl/PIN-PMN-PT(011)heterostructure at room temperature,with a giant electrical modulation of magnetization for which the maximum relative magnetization change(?M/M)is up to 66% was reported in this dissertation.The 109° ferroelastic domain switching in the PIN-PMN-PT and coupling with the ferromagnetic(FM)film via uniaxial anisotropy originating from the PIN-PMN-PT(011)surface are the key roles in converse ME effect.Also a new,four-state memory through which it is possible to modify the remanent magnetism state by adjusting the electric field was proposed.In addition,more precise electrical magnetization modulation,named as electric field control of hard and easy axis respectively,could be obtained both in FeAl/PIN-PMN-PT(011)and FeAl/PIN-PMN-PT(111)structures,and particularly,a new model about magentization process changes dependence of polarization switching was deduced in mechanism discussion on magnetoelectric effect.Finally,the high-frequency characteristic of single ctystal FeAl films were investigated using ferromagnetic resonance(FMR).A resonance frequency of 10.5 GHz was achieved in the Fe/GaAs(001)structure and the high resonance frequency could be changed by altering the Al content in Fe1-xAlx films.By analyzing the reason of resonance frequency changed through external magnetic field and Al proportion,it is found that the resonance linewidth is related to the homogeneous of crystal structure. |
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