Growth-sequence-dependent interface magnetism of SrIrO$_3$ - La$_{0.7}$Sr$_{0.3}$MnO$_3$ bilayers

TL;DR

This study investigates how the growth sequence of SrIrO$_3$ - La$_{0.7}$Sr$_{0.3}$MnO$_3$ bilayers influences interfacial magnetism, revealing significant effects on magnetic order and anisotropy due to interfacial lattice structure and symmetry.

Contribution

It demonstrates that the growth sequence critically affects interfacial magnetic properties in SrIrO$_3$ - La$_{0.7}$Sr$_{0.3}$MnO$_3$ bilayers, highlighting the role of lattice structure and symmetry.

Findings

Growth sequence alters magnetic order and anisotropy.

Strong magnetic changes observed in LSMO on SIO.

Interfacial lattice structure influences magnetic coupling.

Abstract

Bilayers of the oxide 3d ferromagnet La$_{0.7}$Sr$_{0.3}$MnO$_{3}$ (LSMO) and the 5d paramagnet SrIrO$_{3}$ (SIO) with large spin-orbit coupling (SOC) have been investigated regarding the impact of interfacial SOC on magnetic order. For the growth sequence of LSMO on SIO, ferromagnetism is strongly altered and large out-of-plane-canted anisotropy associated with lacking magnetic saturation up to 4 T has been observed. Thin bilayer films have been grown coherently in both growth sequences on SrTiO$_3$ (001) by pulsed laser deposition and structurally characterized by scanning transmission electron microscopy (STEM) and x-ray diffraction (XRD). Measurements of magnetization and field-dependent Mn L$_{2,3}$ edge x-ray magnetic circular dichroism (XMCD) reveal changes of LSMO magnetic order which are strong in LSMO on SIO and weak in LSMO underneath of SIO. We attribute the impact of the growth sequence to the interfacial lattice structure/symmetry which is known to influence the interfacial magnetic coupling.