# Magnetization spin dynamics in a (LuBi)3Fe5O12 (BLIG) epitaxial film

## TL;DR

This paper investigates the magnetic properties and spin wave excitations in (LuBi)3Fe5O12 (BLIG) epitaxial films, combining experimental measurements and micromagnetic simulations to understand their potential for magnonic applications.

## Contribution

It provides new experimental data and micromagnetic simulation analysis of spin wave dynamics in BLIG films, highlighting their high Curie temperature and large Faraday rotation.

## Key findings

- BLIG films exhibit magnetic stripe domains with 1.4 μm width.
- Support thermal magnons at 7 GHz with 400 MHz linewidth.
- Precessional frequency depends on external magnetic field, matching simulations.

## Abstract

Bismuth substituted lutetium iron garnet (BLIG) films exhibit larger Faraday rotation, and have a higher Curie temperature than yttrium iron garnet. We have observed magnetic stripe domains and measured domain widths of 1.4 {\mu}{\mu}m using Fourier domain polarization microscopy, Faraday rotation experiments yield a coercive field of 5 Oe. These characterizations form the basis of micromagnetic simulations that allow us to estimate and compare spin wave excitations in BLIG films. We observed that these films support thermal magnons with a precessional frequency of 7 GHz with a line width of 400 MHz. Further, we studied the dependence of precessional frequency on the externally applied magnetic field. Brillouin light scattering experiments and precession frequencies predicted by simulations show similar trend with increasing field.