Dynamic magnetization of NiZn ferrite doped FeSiAl thin films fabricated by oblique sputtering

•We prepared NiZn ferrite doped FeSiAl-based thin films using oblique deposition technique.•The magnetic properties of FeSiAl-based thin films were systematically studied.•Two ferromagnetic resonance peaks were observed in the permeability spectra.•The thermal stability of microwave properties of FeSiAl-based films was studied.•The thermal stability of properties we studied was relatively good. In this study, we comprehensively investigate the dynamic magnetic properties of FeSiAl-NiZnFeO thin films prepared by the oblique deposition method via a shorted microstrip perturbation technique. For the films with higher oblique angle and NiZn ferrite doping amount, there are two ferromagnetic resonance peaks observed in the permeability spectra, and both of the two peaks originate from FeSiAl. Furthermore, the magnetic anisotropy field HK of the ferromagnetic resonance peak at higher frequency is enhanced with increasing doping amount, which is interpreted in terms of the contribution of reinforced stress-induced anisotropy and shape anisotropy brought about by doping elements and oblique sputtering method. In addition, the thermal stability of the ferromagnetic resonance frequency fFMR of FeSiAl-NiZnFeO films with oblique angles of 35° and 45° with respect to temperature ranging from 300K to 420K is deteriorated with increasing ferrite doping amount, which is mainly ascribed to the influence of pair-ordering anisotropy and/or the reduction of the FeSiAl grain size.