AC Field Assisted Magnetization Reversal in Ferromagnetic Thin Films

Although the effects of high frequency electromagnetic wave on magnetization reversal are extensively studied, the influence of low frequency ac field on magnetization reversal is seldom studied. In this research, the magnetoresistance measurement is performed to study the switching field variation under ac fields of frequencies 25 kHz, 405 kHz, and 750 kHz applied in different directions with respect to ferromagnetic elliptical thin films. It can be observed that the switching fields of the ellipses subject to in-plane ac fields are reduced significantly compared to the case without ac field, the reduction of the switching field can be up to 17% in this experiment. However, the switching fields of the ellipses subject to out-of-plane ac fields are not reduced compared to the case without ac field.