Analysis of power loss in Ni-Zn ferrites

The power loss (P-cv) was analyzed by combining two methods. The first, P-cv, is divided into hysteresis loss (P-h) and residual loss (P-r) from the frequency dependence of the power loss according to the method of Otsuki , and, second, the loss factors are attributed to domain wall motion (P-w) and the rotation magnetization (P-rot) by adapting the method proposed by Visser It was found that P-w coincides with P-h in the lower frequency range, but the difference between them becomes significant as frequency goes up. The higher value of P-w, in comparison with P-h 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 500 kHz, while P-wd becomes predominant factor in the higher frequency range more than 500 kHz. (C) 2000 American Institute of Physics. [S0021- 8979(00)28708-2].