Large exchange bias after zero-field cooling from an unmagnetized state

TL;DR

This paper reports a large exchange bias in Ni-Mn-In alloys after zero-field cooling, attributed to interface formation between magnetic phases during initial magnetization, revealing a novel way to induce EB without field cooling.

Contribution

It introduces a new phenomenon of large exchange bias after zero-field cooling from an unmagnetized state in bulk alloys, linked to interface formation during magnetization.

Findings

Large exchange bias observed after zero-field cooling

Unusual interface formation between magnetic phases

Unidirectional anisotropy created isothermally below blocking temperature

Abstract

Exchange bias (EB) is usually observed in systems with interface between different magnetic phases after field cooling. Here we report an unusual phenomenon in which a large EB can be observed in Ni-Mn-In bulk alloys after zero-field cooling from an unmagnetized state. We propose this is related to the newly formed interface between different magnetic phases during the initial magnetization process. The magnetic unidirectional anisotropy, which is the origin of EB effect, can be created isothermally below the blocking temperature.