Low-field microwave absorption in epitaxial La0.7Sr0.3MnO3 films that results from the angle-tuned ferromagnetic resonance in the multidomain state

We studied magnetic-field-induced microwave absorption in 100-200 nm thick La0.7Sr0.3MnO3 films on SrTiO3 substrate and found a low-field absorption with a very peculiar angular dependence: it appears only in the oblique field and is absent both in the parallel and in the perpendicular orientations. We demonstrate that this low-field absorption results from the ferromagnetic resonance in the multidomain state (domain-mode resonance). Its unusual angular dependence arises from the interplay between the parallel component of the magnetic field that drives the film into multidomain state and the perpendicular field component that controls the domain width through its effect on domain-wall energy. The low-field microwave absorption in the multidomain state can be a tool to probe domain structure in magnetic films with in-plane magnetization.