Thermally driven analog of the Barkhausen effect at the metal-insulator transition in vanadium dioxide
Kwang, Siu Yi
Hardy, Will J.
The physics of the metal-insulator transition (MIT) inﾠvanadiumﾠdioxide remains a subject of intense interest. Because of the complicating effects of elastic strain on the phase transition, there is interest in comparatively strain-free means of examining VO2ﾠmaterial properties.ﾠWe report contact-free, low-strain studies of the MIT through an inductive bridge approach sensitive to the magnetic response of VO2ﾠpowder.ﾠRather than observing the expected step-like change inﾠsusceptibilityﾠat the transition, we argue that theﾠmeasuredﾠresponse is dominated by an analog of theﾠBarkhausen effect,ﾠdue to the extremely sharp jump in the magnetic response of each grain as a function of time as theﾠmaterialﾠis cycled across the phase boundary. This effect suggests that futureﾠmeasurementsﾠcould access the dynamics of this and similar phase transitions.