Microstructure and interface studies of LaVO3/SrVO3 superlattices

TL;DR

This study investigates the microstructure and interfaces of LaVO3/SrVO3 superlattices on SrTiO3 substrates, revealing epitaxial growth, layer distortions, and valence changes through TEM and EELS analyses.

Contribution

It provides detailed TEM and EELS characterization of LaVO3/SrVO3 superlattices, highlighting structural variants, distortions, and valence modifications at interfaces.

Findings

Both layers are epitaxially grown with high crystal quality.

LaVO3 layers exhibit two orientational variants.

Valence changes are observed at the interfaces.

Abstract

The structure and interface characteristics of (LaVO3)6m(SrVO3)m superlattices deposited on (100)-SrTiO3 (STO) substrate were studied using Transmission Electron Microscopy (TEM). Cross-section TEM studies revealed that both LaVO3 (LVO) and SrVO3 (SVO) layers are good single crystal quality and epitaxially grown with respect to the substrate. It is evidenced that LVO layers are made of two orientational variants of a distorted perovskite compatible with bulk LaVO3 while SVO layers suffers from a tetragonal distortion due to the substrate induced stain. Electron Energy Loss Spectroscopy (EELS) investigations indicate changes in the fine structure of the V L23 edge, related to a valence change between the LaVO3 and SrVO3 layers.