Dynamic FMR and magneto-optical response of hydrogenated FCC phase Fe25Pd75 thin films and micro patterned devices

TL;DR

This study explores how hydrogen absorption affects the magnetic and optical properties of Fe25Pd75 thin films, revealing significant FMR shifts and enhanced responses, with potential implications for hydrogen sensing and magnetic device applications.

Contribution

It provides new insights into hydrogen-induced effects on FCC phase Fe25Pd75, combining experimental FMR, magneto-optical, structural studies, and DFT calculations to understand the phenomena.

Findings

Hydrogen absorption causes a significant FMR peak shift towards higher fields.

Hydrogenation leads to a large amplitude FMR response in Fe25Pd75.

The study demonstrates reversible hydrogen cycling effects on magnetic properties.

Abstract

In this work, we investigate the effects of H2 on the physical properties of Fe25Pd75. Broadband ferromagnetic resonance (FMR) spectroscopy revealed a significant FMR peak shift induced by H2 absorption for the FCC phased Fe25Pd75. The peak shifted towards higher applied fields, which is contrary to what was previously observed for CoPd alloys. Additionally, we conducted structural and magneto-optical Kerr ellipsometric studies on the Fe25Pd75 film and performed density functional theory calculations to explore the electronic and magnetic properties in both hydrogenated and dehydrogenated states. In the final part of this study, we deposited a Fe25Pd75 layer on top of a microscopic coplanar transmission line and investigated the FMR response of the layer while driven by a microwave current in the coplanar line. We observed a large amplitude FMR response upon hydrogen absorption, as well as desorption rates when cycling between pure N2 and a mixture of 3% H2 + 97% N2.