Insulating-to-Conducting Behavior and Band Profile Across the La0.9Ba0.1MnO3/Nb:SrTiO3 Epitaxial Interface

TL;DR

This study investigates the electronic structure and interface band profile of La0.9Ba0.1MnO3 thin films on Nb:SrTiO3, revealing a thickness-dependent transition from insulating to conducting behavior and the formation of a type II heterojunction.

Contribution

It provides detailed insights into the electronic structure and interface band alignment of La0.9Ba0.1MnO3/Nb:SrTiO3 heterostructures using electrical and photoemission spectroscopy.

Findings

Observed a transition from insulating to conducting with increasing film thickness.

Determined the interface band diagram showing a type II heterojunction.

Provided insights into thickness-dependent electronic properties of the heterostructure.

Abstract

La0.9Ba0.1MnO3 is a ferromagnetic insulator in its bulk form, but exhibits metallicity in thin film form. It has a wide potential in a range of spintronic-related applications, and hence it is critical to understand thickness-dependent electronic structure in thin films as well as substrate/film interface effects. Here, using electrical and in-situ photoemission spectroscopy measurements, we report the electronic structure and interface band profile of high-quality layer-by-layer-grown La0.9Ba0.1MnO3 on single crystal Nb:SrTiO3 substrates. A transition from insulating-to-conducting was observed with increasing La0.9Ba0.1MnO3 thickness, which was explained by the determined interface band diagram of La0.9Ba0.1MnO3/Nb: SrTiO3, where a type II heterojunction was formed.