Micromagnetic Simulation Of Domain Structure And Ferromagnetic Resonance In Stripe Domain Film

Soft magnetic thin films have great potential in spintronics and microwave devices,so it is necessary to deeply understand the microstructural features and micromagnetic properties of thin films,as well as how external conditions determine their domain structure and how to tune them.The results of studying the domain structure and dynamic response of thin films will provide theoretical and practical basis for the application of soft magnetic thin films in high frequency magnetic devices.In this paper,the soft magnetic films with striped domains are taken as the research object,and the microwave magnetism of acoustic film and optical mode resonance in the stripe domain thin films is studied and regulated by means of micromagnetism.The main research contents are as follows:1.This paper discusses the reasons for the formation of domain structure,and discusses the domain structure models of striped domains: sawtooth wave model,square wave model and triangle wave model.The research results show that the component of the magnetic moment signal in the z direction has a trend of changing from a sine wave-like square wave from the surface of the film to the inside of the film,and gradually becomes larger.It shows that as the depth of the film increases,the angle between the magnetic moment and the plane direction of the film becomes larger and larger.2.The effects of micromagnetic simulation parameters and external conditions on domain structure are discussed by changing the parameters of micromagnetic simulation,such as film thickness,anisotropy constant,exchange stiffness coefficient,saturation magnetization,damping factor,temperature and external magnetic field.From the perspective of energy,the competition among anisotropy energy,exchange energy and demagnetizing energy affects the change of domain structure.The relationship between quality factor Q,thickness and exchange length is studied.The stripe domain is above the critical curve and the in-plane domain is below the critical curve.3.Micromagnetic simulations of the microwave and magnetic fields of the same sample in different directions are carried out to explore the variation of acoustic and optical modes of the stripe domain from the perspective of thickness and direction.This elucidates the magnetization dynamics of the film’s high-frequency response and the physical mechanism of microwave magnetism.