Brillouin Light Scattering Spectra as local Temperature Sensors for Thermal Magnons and Acoustic Phonons

TL;DR

This paper demonstrates that micro-Brillouin light scattering can serve as a precise local temperature sensor for magnons and phonons, enabling detailed thermal analysis in magnetic and non-magnetic materials.

Contribution

It introduces a novel application of micro-BLS as a local temperature measurement tool for thermal magnons and acoustic phonons with high resolution.

Findings

Achieved temperature resolution better than 2.5 K.

Measured local temperatures across thermal gradients.

Validated micro-BLS as a tool for spin caloritronic studies.

Abstract

We demonstrate the use of the micro-Brillouin light scattering (micro-BLS) technique as a local temperature sensor for magnons in a Permalloy thin film and phonons in the glass substrate. A systematic shift in the frequencies of two thermally excited perpendicular standing spin wave modes as the film is uniformly heated allows us to achieve a temperature resolution better than 2.5 K. We demonstrate that the micro-BLS spectra can be used to measure the local temperatures of phonons and magnons across a thermal gradient. Such local temperature sensors are useful for investigating spin caloritronic and thermal transport phenomena in general.