Study On The Magnetization Characteristics Of Amorphous Wires Based On Micromagnetics

Due to the good magnetic properties, the amorphous wires are suitable for material of magnetic sensor based on the GMI effect. Current researchers mostly use experimental method to study the magnetization and magnetization reversal in amorphous wires by Kerr effect which can be used to observe the domain structure on the surface of amorphous wires but can’t show the evolution and the distribution of magnetic moments in amorphous wires.Appropriate models of Co-based amorphous wires are established by combining with micro-magnetic theory and numerical calculation method. And the study on the magnetization characteristics of amorphous wires is based on the distribution and evolution of magnetic moments in amorphous wires. Firstly, in this paper, the expressions of demagnetizing field and demagnetizing factor s in the axially and uniformly magnetized amorphous wire are derived by numerical calculation method on the basis of magnetic charge viewpoint. The relations of demagnetizing factors to the size of amorphous wire and the spa tial location in amorphous wire are analysed according to the simulation results. And we found that the axial demagnetizing factor is large at the end and small in the middle of amorphous wire, et al. Next, two domain structure models of the Co-based amorphous wires, bamboo domain structure model without nuclear and core-shell domain structure model, are established according to the fact. Then the micro-magnetic simulation of the two models applied axial external field and non-axial external field sequentially are launched. The distribution and evolution of magnetic moments from current saturation state to the opposite saturation state are observed from the suitable locations which are selected according to the characteristics of demagnetizing factors and are used to analysis the relation of directions of external field to the magnetization characteristics of amorphous wires. At last, the anisotropy of the two models are set to circumferential anisotropy and helical anisotropy sequentially. And the influence of different anisotropy on the magnetization and magnetization reversal of amorphous wires are studied by the distributions of magnetic moments and the hysteresis of amorphous wires from micro-magnetic simulation.