On the interpretation of the angular dependence of the FMR spectrum in heterogeneous ferromagnetic thin films

TL;DR

This paper explains how the angular dependence of FMR spectra in heterogeneous ferromagnetic thin films can be understood by analyzing specific magnetic field configurations where the resonance condition becomes insensitive to effective magnetization variations.

Contribution

It introduces a condition under which multi-peak FMR spectra in heterogeneous films collapse into a single peak, clarifying the interpretation of FMR measurements.

Findings

Multi-peak FMR spectra can unify into a single peak under specific field configurations.

The condition dH_res/dM_eff=0 explains the collapse of spectra.

This insight aids in interpreting complex FMR spectra in heterogeneous ferromagnetic films.

Abstract

We demonstrate that a multi-peak FMR spectrum, with lines corresponding to resonance in different ferromagnetic regions of a heterogeneous thin-film sample, can collapse to a single-peak spectrum if there exists a particular field configuration, or the configuration of the external magnetic field with respect to the film surface, in which $dH_{\text{res}}/dM_{\text{eff}}=0$ within the region magnetically dominating in the sample.