Analysis of Power Loss in Ni-Zn Ferrites

摘要

Power loss in Ni-Zn ferrites was analyzed by combining two methods. At first, P_(cv) was divided into hysteresis loss(P_h) and residual loss(P_r) according to the method of Otsuki et al. The hysteresis loss dominates P_(cv) in the frequency range below 500kHz, while P_r becomes a predominant factor in the higher frequency range above 500kHz. Secondly, the loss factors which were attributed to domain wall motion(P_w) and rotation magnetization(P_(rot)) were obtained by adapting the method proposed by Visser et al. According to the loss analysis, P_w dominates P_(cv) in the measured frequency range. It was found, by comparing the loss factors obtained by two methods, that P_w coincides with P_h in the lower frequency range, but the difference between them becomes significant as the frequency increases. The higher value of P_w in comparison with Ph in the higher frequency range, can be attributed to the enhancement of loss due to the dynamic motion of the domain wall(P_(wd)) by raising the frequency. The hysteresis loss dominates P_(cv) in the frequency range below 500kHz, while P_(wd) becomes a predominant factor in the higher frequency range above 500kHz.