Interface Magnetoresistance in Manganite-Titanate Heterojunctions

TL;DR

This paper investigates magnetoresistance effects in manganite-titanate heterojunctions, revealing a new interface magnetoresistance mechanism driven by magnetic field-induced band diagram changes due to strong electron-spin coupling.

Contribution

It introduces a novel form of magnetoresistance in manganite-titanate interfaces caused by magnetic field effects on the interface band structure.

Findings

Current-voltage behavior fits thermally-assisted tunneling model without magnetic field.

Magnetic field causes significant deviation in oxygen-deficient junctions.

New magnetoresistance mechanism linked to interface band diagram changes.

Abstract

We have found that the current- voltage characteristics of La0.7Sr0.3MnO3(-delta)/Nb:SrTiO3 rectifying junctions are quantitatively well-described by (thermally-assisted) tunneling with an effectively temperature-independent Schottky barrier under no magnetic field, while those of the oxygen deficient junction remarkably deviate from such a simple behavior as magnetic field is applied. These results indicate a new form of magnetoresistance arising from magnetic field changes of the interface band diagram via the strong electron-spin coupling in manganites.