Micromagnetic simulation of high frequency magnetic characteristics for Fe-based nanocrystalline alloy

摘要

Fe-based nanocrystalline soft magnetic alloy, namely nanocrystalline core, has been considered to be an ideal iron-core material in power system. The equivalent model of nanocrystalline core was established at mesoscopic scale by using three-dimensional micromagnetic simulation, and the static and high-frequency magnetic characteristics of the cores were studied separately. Under DC magnetic field, the magnetization curve and hysteresis loop were measured, the transition process of magnetic domain structure and spins orientation during magnetization and magnetization reversal in cores were analyzed as well. Permeability, which represents a kind of degree of magnetization in respond to a given magnetic field, was taken as the object of study. Under the alternating field, influences of frequency change on permeability of the cores were studied within a frequency range of 100MHz~900MHz. Under the hybrid field with frequency of 100MHz, the effects of DC biasing on permeability was analyzed while different bias magnetic field was applied. The results suggested the cores do have good magnetic properties. With the increasing of frequency, for complex permeability of nanocrystalline cores, the real part which indicates energy storage decreased slowly, while the imaginary part which indicates energy consumption increased rapidly. On the contrary, with the increasing of DC biasing, the real part increased while the imaginary part decreased quickly. The simulation provides some reference for future application of nanocrystalline cores in high-frequency electronic instruments.