Antiferromagnetic coupling and enhanced magnetization in all-ferromagnetic superlattices

TL;DR

This study investigates the magnetic interactions in all-ferromagnetic superlattices of LSMO and SRO, revealing antiferromagnetic coupling and enhanced magnetization due to interfacial effects.

Contribution

It provides new insights into the magnetic coupling and magnetization enhancement in LSMO/SRO superlattices, highlighting the role of interface chemistry.

Findings

Observation of antiferromagnetic coupling between layers.

Enhanced saturation magnetization in thin SRO layers.

Magnetic behavior linked to interfacial stereochemistry modifications.

Abstract

The structural and magnetic properties of a series of superlattices consisting of two ferromagnetic metals La$_{0.7}$Sr$_{0.3}$MnO$_3$ (LSMO) and SrRuO$_3$ (SRO) grown on (001) oriented SrTiO$_3$ are studied. Superlattices with a fixed LSMO layer thickness of 20 unit cells (u.c.) and varying SRO layer thickness show a sudden drop in magnetization on cooling through temperature where both LSMO and SRO layers are ferromagnetic. This behavior suggests an antiferromagnetic coupling between the layers. In addition, the samples having thinner SRO layers (n \TEXTsymbol{<} 6) exhibit enhanced saturation magnetization at 10 K. These observations are attributed to the possible modification in the stereochemistry of the Ru and Mn ions in the interfacial region.