Angular dependence of spin wave resonance in FeNi–MgO granular film

Abstract

We study the angle dependence of the spin wave resonance spectra in FeNi–MgO granular films fabricated by magnetron sputtering, using ferromagnetic resonance technology. Seven Portis-type spin resonances with the same magnetic field spacing are observed when the magnetic field is perpendicular to the film. By varying the field angle θH, we find that there are at least two resonance modes at θH = 14°, indicating that the critical angle θc of the ferromagnetic resonance mode is in the range of 14°–15°. Furthermore, we obtained the exchange stiffness constant and distortion parameter through the surface inhomogeneity model and the volume inhomogeneity model. Moreover, in order to figure out the types of spin wave, we also investigate the dependence of spin wave resonance spectra on temperature, which reveals an excitation of the perpendicular spin standing wave.