Exchange bias effect in antiferromagnets containing ferromagnetic clusters

Abstract

This study offers an explanation for the occurrence of magnetization exchange bias in antiferromagnets with ferromagnetic inclusions during pre-cooling the system in a magnetic field. The ferromagnetic (FM) subsystem ordered in this field at the Néel temperature leads to an inhomogeneous state of the antiferromagnetic (AFM) matrix with the finite mean effective field at the FM/AFM interface. This field causes exchange bias in the dependence M = M(H) during further remagnetization of the heterogeneous system. To describe the proposed scenario for such an effect, a simple model of a two-dimensional system with round inclusions of the FM phase was considered. Using numerical calculations and previously obtained analytical results, the study determines magnetization dependencies on the external field, which qualitatively explains the features of exchange bias in experimentally studied heterogeneous systems.

Exchange Bias State at the Crossover to 2D Ferromagnetism

“…The idea is not new. Electronic phase separation is commonly considered as the physical mechanism of intrinsic EB effects in manganites. − A simple model for the EB effect in antiferromagnets containing FM clusters has been proposed in ref . A detailed study of the effect in GdSi 2 presents a problem because the electronic structure is not known: theoretical studies of GdSi 2 and related systems predict magnetic properties disagreeing with the experiment.…”

Intrinsic exchange bias state in silicene and germanene materials EuX2

“…A simple model to describe EB in antiferromagnets containing FM clusters has been proposed in Ref. 51.…”