Electronic reconstruction at the isopolar LaTiO3/LaFeO3 interface: An x-ray photoemission and density functional theory study

TL;DR

This study combines x-ray photoemission and density functional theory to reveal how electronic reconstruction occurs at the LaTiO3/LaFeO3 interface, leading to significant charge transfer and new insulating states.

Contribution

It provides a detailed understanding of the electronic reconstruction mechanism at the isopolar LaTiO3/LaFeO3 interface, highlighting the role of band alignment and crystal field effects.

Findings

Formation of a non-magnetic band insulator at the interface

Charge transfer of approximately 1.2 electrons per interface unit cell

Rearrangement of Fe 3d bands confirmed by spectroscopy

Abstract

We report the formation of a non-magnetic band insulator at the isopolar interface between the antiferromagnetic Mott-Hubbard insulator LaTiO3 and the antiferromagnetic charge transfer insulator LaFeO3. By density functional theory calculations, we find that the formation of this interface state is driven by the combination of O band alignment and crystal field splitting energy of the t2g and eg bands. As a result of these two driving forces, the Fe 3d bands rearrange and electrons are transferred from Ti to Fe. This picture is supported by x-ray photoelectron spectroscopy, which confirms the rearrangement of the Fe 3d bands and reveals an unprecedented charge transfer up to 1.2+/-0.2 e-/interface unit cell in our LaTiO3/LaFeO3 heterostructures.