Thermally driven analog of the Barkhausen effect at the metal-insulator transition in vanadium dioxide

• Published in: Applied physics letters Vol. 105; no. 13
• Main Authors: Huber-Rodriguez, Benjamin, Kwang, Siu Yi, Hardy, Will J., Ji, Heng, Chen, Chih-Wei, Morosan, Emilia, Natelson, Douglas
• Format: Journal Article
• Language: English
• Published: Melville American Institute of Physics 29.09.2014
• Subjects: Applied physics; Barkhausen effect; Bridge approaches; CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; DIELECTRIC MATERIALS; Insulators; Magnetic permeability; Material properties; Metal-insulator transition; METALS; PHASE TRANSFORMATIONS; Phase transitions; Strain; STRAINS; TIME DEPENDENCE; Vanadium dioxide; VANADIUM OXIDES
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.4896624

The physics of the metal-insulator transition (MIT) in vanadium dioxide 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 VO2 material properties. We report contact-free, low-strain studies of the MIT through an inductive bridge approach sensitive to the magnetic response of VO2 powder. Rather than observing the expected step-like change in susceptibility at the transition, we argue that the measured response is dominated by an analog of the Barkhausen effect, due to the extremely sharp jump in the magnetic response of each grain as a function of time as the material is cycled across the phase boundary. This effect suggests that future measurements could access the dynamics of this and similar phase transitions.