Magnetic hysteresis in the Cu-Al-Mn intermetallic alloy: experiments and modeling

TL;DR

This study investigates magnetic hysteresis in Cu-Al-Mn alloys through experiments and modeling, revealing how temperature and Mn content influence hysteresis characteristics and demonstrating the model's ability to replicate experimental observations.

Contribution

The paper introduces a zero-temperature site-diluted Ising model that accurately reproduces experimental hysteresis features in Cu-Al-Mn alloys, linking disorder effects to critical behavior.

Findings

Hysteresis cycles change from smooth to sharp with increasing Mn content at low temperatures.

The model captures the main experimental hysteresis features.

Disorder induces a critical line separating disordered and ferromagnetic phases.

Abstract

We study isothermal magnetization processes in the Cu-Al-Mn intermetallic alloy. Hysteresis is observed at temperatures below the spin-freezing of the system. The characteristics of the hysteresis cycles as a function of temperature and Mn content (magnetic element) are obtained. At low temperature (5 K) a change from smooth to sharp cycles is observed with increasing Mn content, which is related to the decrease of configurational disorder. We also study a zero-temperature site-diluted Ising model, suitable for the description of this Cu-Al-Mn system. The model reproduces the main features of the hysteresis loops observed experimentally. It exhibits a disorder-induced critical line separating a disordered phase from an incipient ferromagnetic ground-state. The comparison between the model and the experiments allows to conclude that the observed change in the experimental hysteresis loops can be understood within the framework of the theory of disorder-induced criticality in fluctuationless first-order phase transitions.