Magneto-transport and domain wall scattering in epitaxy $L1_{0}$ MnAl thin film

TL;DR

This paper investigates temperature-dependent magneto-transport behaviors in epitaxial $L1_{0}$ MnAl thin films, revealing distinct negative and positive magnetoresistance regimes linked to domain wall dynamics and Lorentz effects.

Contribution

It demonstrates the coexistence of two magneto-transport mechanisms in MnAl films and correlates domain wall density with resistivity changes across temperatures.

Findings

Negative MR above 175 K with increased resistivity at coercive fields.

Positive quadratic MR below 175 K dominated by Lorentz effects.

Quantitative correlation between domain wall density and resistivity.

Abstract

This work demonstrated two different kinds of magneto-transport behaviors in epitaxial $L1_{0}$ MnAl film as a function of temperature. The magneto-resistance ratio (MR) was negative and exhibited evident enhancement in the resistivity at coercive fields above 175 K. The MR enhancement was attributed to the increase of the magnetic domain walls based on the quantitative correlation between the domain density and the resistivity. Below 175 K, the MR was positive and showed a quadratic dependence on the external magnetic field, which implied that the MR was dominated by Lorentz effects.