Unification of bulk and interface electroresistive switching in oxide systems

TL;DR

This paper reveals that electroresistive switching in oxide Schottky systems is driven by electroformation and impact ionization, involving atomic rearrangements that affect the bulk charge region rather than just the interface.

Contribution

It unifies the understanding of bulk and interface electroresistive switching mechanisms in oxide systems through experimental evidence and modeling.

Findings

Electroformation causes switching in oxide Schottky systems.

Impact ionization is responsible for negative resistance in hysteretic curves.

Atomic rearrangements involve the charge space region, not just the interface.

Abstract

We demonstrate that the physical mechanism behind electroresistive switching in oxide Schottky systems is electroformation, as in insulating oxides. Negative resistance shown by the hysteretic current-voltage curves proves that impact ionization is at the origin of the switching. Analyses of the capacitance-voltage and conductance-voltage curves through a simple model show that an atomic rearrangement is involved in the process. Switching in these systems is a bulk effect, not strictly confined at the interface but at the charge space region.