FeCo薄膜微波磁导率谱的磁滞特性研究

Magnetic hysteresis in microwave permeability of ferromagnetic FeCo films

测量了FeCo薄膜在0.5-8 GHz频率范围内的复数磁导率谱，通过改变外加磁场 H ex 的方向、大小，研究磁导率虚部共振曲线出现的磁滞现象。验证了样品铁磁共振频率f r 的平方值随正向H ex 线性变化的规律；观察到 H ex 与样品磁化方向相反时，共振曲线的磁滞现象，尤其是 H ex 的值接近矫顽力H c时，共振曲线出现双峰，反映了铁磁薄膜中部分磁矩随着反向H ex 逐渐增大逐步翻转的磁化动力学过程。由铁磁共振公式拟合磁谱虚部曲线，计算了双共振峰出现时薄膜中磁矩发生翻转的比例。

The dynamic magnetic properties of a 200-nm-thick FeCo film had been surveyed through permeabili-ty measurements in the frequency range of 0.5 to 8 GHz,within a magnetic field applied in the easy magnetic direction.When the external field was inversed with the orientation of the magnetization,the increase of the field leads to the decrease of the resonance frequency according to the magnetic hysteresis that shown in the fer-romagnetic films.The phenomenon can be explained by ferromagnetic resonance equations and the ratio of mag-netic moments in the opposite directions has been calculated.