A Training effect on electrical properties in nanoscale BiFeO$_3$

TL;DR

This study investigates how repeated electric cycling influences the electrical properties of nanoscale BiFeO₃, revealing a defect migration process that stabilizes the material's behavior, which is crucial for nanoelectronic applications.

Contribution

It demonstrates the existence of a training effect in nanoscale BiFeO₃ and characterizes the defect migration process leading to a stable electrical state.

Findings

Optimal cycling stabilizes electrical properties.

Defect migration follows a glass-transition-like process.

Training effect is common in oxide nanostructures.

Abstract

We report our observation of the training effect on dc electrical properties in a nanochain of BiFeO$_3$ as a result of large scale migration of defects under combined influence of electric field and Joule heating. We show that an optimum number of cycles of electric field within the range zero to $\sim$1.0 MV/cm across a temperature range 80-300 K helps in reaching the stable state via a glass-transition-like process in the defect structure. Further treatment does not give rise to any substantial modification. We conclude that such a training effect is ubiquitous in pristine nanowires or chains of oxides and needs to be addressed for applications in nanoelectronic devices.