Low-field microwave absorption in epitaxial La-Sr-Mn-O films resulting from the angle-tuned ferromagnetic resonance in the multidomain state

TL;DR

This study reveals a unique low-field microwave absorption in La-Sr-Mn-O films caused by angle-dependent ferromagnetic resonance in the multidomain state, offering a new method to probe domain structures.

Contribution

It demonstrates the angular dependence of low-field microwave absorption due to domain-mode resonance in ferromagnetic films, highlighting a novel way to analyze domain structures.

Findings

Low-field absorption appears only in oblique magnetic fields.

The absorption results from ferromagnetic resonance in the multidomain state.

Angular dependence is influenced by the magnetic field components affecting domain walls.

Abstract

We studied magnetic-field induced microwave absorption in 100-200 nm thick La$_{0.7}$Sr$_{0.3}$MnO$_{3}$ films on SrTiO$_{3}$ 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.