Element-Specific Depth Profile of Magnetism and Stoichiometry at the La0.67Sr0.33MnO3/BiFeO3 Interface

TL;DR

This study uses advanced reflectometry techniques to map element-specific magnetic and chemical profiles at the La0.67Sr0.33MnO3/BiFeO3 interface, revealing a magnetically diluted layer linked to compositional changes.

Contribution

It provides the first element-specific depth profile of magnetism and stoichiometry at this heterostructure interface with sub-nanometer resolution.

Findings

Identification of a magnetically diluted interface layer.

Correlation between chemical composition and magnetic moment reduction.

Element-specific profiles of Fe and Mn at the interface.

Abstract

Depth-sensitive magnetic, structural and chemical characterization is important in the understanding and optimization of novel physical phenomena emerging at interfaces of transition metal oxide heterostructures. In a simultaneous approach we have used polarized neutron and resonant X-ray reflectometry to determine the magnetic profile across atomically sharp interfaces of ferromagnetic La0.67Sr0.33MnO3 / multiferroic BiFeO3 bi-layers with sub-nanometer resolution. In particular, the X-ray resonant magnetic reflectivity measurements at the Fe and Mn resonance edges allowed us to determine the element specific depth profile of the ferromagnetic moments in both the La0.67Sr0.33MnO3 and BiFeO3 layers. Our measurements indicate a magnetically diluted interface layer within the La0.67Sr0.33MnO3 layer, in contrast to previous observations on inversely deposited layers. Additional resonant X-ray reflection measurements indicate a region of an altered Mn- and O-content at the interface, with a thickness matching that of the magnetic diluted layer, as origin of the reduction of the magnetic moment.