Redox reaction enhanced Schottky contact at a \LNO{}(001)/Al interface

TL;DR

This study demonstrates a diode-like LaNiO3/Al interface where a redox reaction modulates electrical conductivity, showing a significant electro-resistive effect driven by charge transfer and interface chemistry.

Contribution

It reveals a redox reaction mechanism at oxide/metal interfaces that enables reversible control of electrical properties in LaNiO3/Al junctions.

Findings

Electro-resistive effect up to 10^5% observed.

Redox reactions at the interface modulate conductivity.

Reversible switching between insulating and metallic states.

Abstract

Emergent phenomena at interfaces between oxides and metals can appear due to charge transfer and mass transport that modify the bulk properties. By coating the metallic oxide LaNiO$_3$ by aluminium, we fabricated a junction exhibiting a diode-like behaviour. At the equilibrium, the interface is insulating. The metallic behaviour can be recovered by applying a voltage drop across the junction in one polarity only. The electrical properties in direct and reverse bias are investigated. The observed electro-resistive effect rises up to $10^5$ \% and can be interpreted in terms of (i) a spontaneous redox reaction occurring at the interface and (ii) its reversal induced by charge injection in direct bias.