Interface reconstruction in V-oxide heterostructures determined by x-ray absorption spectroscopy

TL;DR

This study uses x-ray absorption spectroscopy to analyze how the valence state of vanadium varies with layer thickness in LaVO3/LaAlO3 heterostructures, revealing interface and bulk reconstruction effects.

Contribution

It provides new insights into the valence state changes and interface reconstruction mechanisms in V-oxide heterostructures with varying layer thicknesses.

Findings

Valence of V depends on LAO layer thickness.

Transition between electronic and chemical reconstruction observed.

Presence of V^{4+} in thicker LVO layers affects valence state.

Abstract

We present an x-ray absorption study of the dependence of the V oxidation state on the thickness of LaVO$_3$ (LVO) and capping LaAlO$_3$ (LAO) layers in the multilayer structure of LVO sandwiched between LAO. We found that the change of the valence of V as a function of LAO layer thickness can be qualitatively explained by a transition between electronically reconstructed interfaces and a chemical reconstruction. The change as a function of LVO layer thickness is complicated by the presence of a considerable amount of V$^{4+}$ in the bulk of the thicker LVO layers.