Nanoscale Imaging and Control of Resistance Switching in VO[sub]2 at Room Temperature

Abstract

We demonstrate controlled local phase switching of a VO[sub]2 film using a biased conducting atomic force microscope tip. After application of an initial, higher ‘training’ voltage, the resistance transition is hysteretic with IV loops converging upon repeated voltage sweep. The threshold Vset to initiate the insulator-to-metal transition is on order ∼ 5 V at room temperature, and increases at low temperature. We image large variations in Vset from grain to grain. Our imaging technique opens up the possibility for an understanding of the microscopic mechanism of phase transition in VO[sub]2 as well as its potential relevance to solid state devices.