The role of single oxygen or metal induced defect and correlated multiple defects in the formation of conducting filaments

TL;DR

This paper investigates how single and multiple oxygen and metal induced defects influence the formation of conducting filaments in transition metal oxides, highlighting the importance of correlated atomic rearrangements.

Contribution

It introduces a correlated multiple defect model that explains the dominance of oxygen defects in resistive switching, resolving discrepancies with previous simple defect models.

Findings

Metal induced defects are energetically preferable to oxygen defects in single defect models.

Simple multiple defect models without atomic correlation fail to explain experimental observations.

Correlated multiple defect models successfully account for atomic ordering and defect formation in filaments.

Abstract

We study the dependence of the formation energies of oxygen and metal induced defects in Ta2O5, TaO2, TaO, TiO2 and Ti4O7 on the chemical potential of electron and atomic constitutes. In the study of single defect, metal induced defects are found to be preferable to oxygen induced defects. This is against the experimental fact of the dominant role of oxygen induced defects in the RS process. A simple multiple defects picture without correlated atomic rearrangement does not cure this problem. The problem is resolved under the correlated multiple defect picture where the multiple defects result in correlated atomic rearrangement and the final products show certain atomic ordering.