Electrical Breakdown in a V2O3 device at the Insulator to Metal Transition

TL;DR

This study investigates electrical breakdown phenomena in V2O3 thin films at the insulator-metal transition, revealing electro-thermal domain formation and hysteresis effects through experiments and modeling.

Contribution

It provides new insights into the breakdown mechanism involving electro-thermal domains and models these effects with a resistor network approach.

Findings

Electrical breakdown involves electro-thermal domain formation.

Hysteresis and training effects observed in IV curves.

Numerical model reproduces breakdown and hysteresis phenomena.

Abstract

We have measured the electrical properties of a V2O3 thin film micro bridge at the insulator metal transition (IMT). Discontinuous jumps to lower voltages in the current voltage characteristic (IV) followed by an approximately constant voltage progression for high currents indicate an electrical breakdown of the device. In addition, the IV curve shows hysteresis and a training effect, i.e. the subsequent IV loops are different from the first IV loop after thermal cycling. Low temperature scanning electron microscopy (LTSEM) reveals that the electrical breakdown over the whole device is caused by the formation of electro-thermal domains (ETDs), i.e. the current and temperature redistribution in the device. On the contrary, at the nanoscale, the electrical breakdown causes the IMT of individual domains. In a numerical model we considered these domains as a network of resistors and we were able to reproduce the electro-thermal breakdown as well as the hysteresis and the training effect in the IVs.