Electrical breakdown in a V ₂ O ₃ device at the insulator-to-metal transition

Abstract

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