Evidence of orbital reconstruction at interfaces in La0.67Sr0.33MnO3 films

TL;DR

This paper reports the discovery of a universal orbital reconstruction at interfaces in La0.67Sr0.33MnO3 films, characterized by preferential 3d-eg(3z2-r2) orbital occupation that suppresses double exchange, independent of external factors.

Contribution

It provides experimental evidence of a universal orbital reconstruction at interfaces in La0.67Sr0.33MnO3 films, revealing a new surface orbital configuration.

Findings

Identification of LD signature indicating orbital reconstruction

Reconstruction suppresses double exchange mechanism

Independent of strain, substrate, and capping effects

Abstract

Electronic properties of transition metal oxides at interfaces are influenced by strain, electric polarization and oxygen diffusion. Linear dichroism (LD) x-ray absorption, diffraction, transport and magnetization on thin La0.7Sr0.3MnO3 films, allow identification of a peculiar universal interface effect. We report the LD signature of preferential 3d-eg(3z2-r2) occupation at the interface, suppressing the double exchange mechanism. This surface orbital reconstruction is opposite of that favored by residual strain and independent of dipolar fields, chemical nature of the substrate and capping.