Ferromagnetic order of ultra-thin La0.7Ba0.3MnO3 sandwiched between SrRuO3 layers

TL;DR

This study demonstrates that ultra-thin La0.7Ba0.3MnO3 layers maintain ferromagnetic order when sandwiched between SrRuO3 layers, with enhanced Curie temperature and stable magnetism due to interface effects and magnetic coupling.

Contribution

It reveals that coherent interfaces with SrRuO3 stabilize ferromagnetism in monolayer La0.7Ba0.3MnO3, increasing its Curie temperature and magnetic stability, supported by experimental and theoretical analysis.

Findings

Ferromagnetic order persists in 1-unit-cell LBMO at 130 K.

Interface with SRO enhances LBMO Curie temperature.

Magnetic coupling and structural coherence stabilize ferromagnetism.

Abstract

We demonstrate the stability of ferromagnetic order of one unit cell thick optimally doped manganite (La0.7Ba0.3MnO3, LBMO) epitaxially grown between two layers of SrRuO3 (SRO) by using x-ray magnetic circular dichroism. At low temperature LBMO shows an inverted hysteresis loop due to the strong antiferromagnetic coupling to SRO. Moreover, above SRO TC the manganite still exhibits magnetic remanence. Density Functional Theory calculations show that coherent interfaces of LBMO with SRO hinder electronic confinement and the strong magnetic coupling enables the increase of the LBMO TC. From the structural point of view, interfacing with SRO enables LBMO to have octahedral rotations similar to bulk. All these factors jointly contribute for stable ferromagnetism up to 130 K for a one unit cell LBMO film.