Nanoscale magnetic structure of ferromagnet/antiferromagnet manganite multilayers

TL;DR

This study investigates the nanoscale magnetic structure of LSMO/PCMO multilayers using polarized neutron reflectometry, revealing how layer thickness influences magnetic phase separation and strain effects.

Contribution

It provides new insights into how layer thickness controls magnetic phase separation and strain accommodation in manganite superlattices.

Findings

Maximum FM contribution at t_A~3 nm due to cluster size matching

Magnetic frustration at LSMO/PCMO interfaces

Strain conditions optimize FM cluster stability

Abstract

Polarized Neutron Reflectometry and magnetometry measurements have been used to obtain a comprehensive picture of the magnetic structure of a series of La{2/3}Sr{1/3}MnO{3}/Pr{2/3}Ca{1/3}MnO{3} (LSMO/PCMO) superlattices, with varying thickness of the antiferromagnetic (AFM) PCMO layers (0<=t_A<=7.6 nm). While LSMO presents a few magnetically frustrated monolayers at the interfaces with PCMO, in the latter a magnetic contribution due to FM inclusions within the AFM matrix was found to be maximized at t_A~3 nm. This enhancement of the FM moment occurs at the matching between layer thickness and cluster size, where the FM clusters would find the optimal strain conditions to be accommodated within the "non-FM" material. These results have important implications for tuning phase separation via the explicit control of strain.