Interfacial Magnetism in Manganite Superlattices

TL;DR

This study models interfacial magnetism in manganite superlattices, revealing how magnetic moments vary with layer thickness and offering insights to enhance tunneling magnetoresistance by preventing magnetic dead layers.

Contribution

The paper introduces a comprehensive theoretical framework incorporating multiple interactions to explain non-monotonic interfacial magnetism in FM/AFI manganite superlattices.

Findings

Magnetic moments in AFI layers vary non-monotonically with layer width.

The non-monotonic behavior correlates with FM interface magnetization.

Insights suggest ways to improve tunneling magnetoresistance by avoiding magnetic dead layers.

Abstract

We use a two-orbital double-exchange model including Jahn-Teller lattice distortions, superexchange interactions, and long-range Coulomb (LRC) interactions to investigate the origin of magnetically disordered interfaces between ferromagnetic metallic (FM) and antiferromagnetic insulating (AFI) manganites in FM/AFI superlattices. The induced magnetic moment in the AFI layer varies non-monotonically with increasing AFI layer width as seen in the experiment. We provide a framework for understanding this non-monotonic behavior which has a one-to-one correspondence with the magnetization of the FM interface. The obtained insights provide a basis for improving the tunneling magnetoresistance in FM/AFI manganite superlattices by avoiding a magnetic dead layer (MDL) in the FM manganite.