Detecting slow magnetization relaxation via magnetotransport measurements based on the current-reversal method

TL;DR

This paper introduces a robust magnetotransport measurement technique using current-reversal to detect slow magnetization relaxation in magnetic materials, demonstrated on specific trilayer and film systems.

Contribution

It presents a novel application of the current-reversal method for screening slow magnetization relaxation, offering a simple and sensitive alternative to traditional ac lock-in techniques.

Findings

The dc current-reversal method effectively detects relaxation times on the order of seconds.

The approach is demonstrated on Pt/Co/AlOx trilayers and { au}-MnAl films.

It shows higher sensitivity to slow relaxation processes compared to ac lock-in methods.

Abstract

Slow magnetization relaxation processes are an important time-dependent property of many magnetic materials. We show that magnetotransport measurements based on a well-established current-reversal method can be utilized to implement a simple and robust screening scheme for such relaxation processes. We demonstrate our approach considering the anomalous Hall effect in a Pt/Co/AlOx trilayer model system, and then explore relaxation in {\tau} -MnAl films. Compared to magnetotransport experiments based on ac lock-in techniques, we find that the dc current-reversal method is particulary sensitive to relaxation processes with relaxation time scales on the order of seconds, comparable to the current-reversal measurement time scales.