Presentation Information
[3F13]Nanoscale dynamics of metal–insulator transition in VO2 thin film by IR s-SNOM
*Kyungmin Kim1, Linfeng Hou1, Jun Nishida2, Takashi Kumagai2, Masayuki Abe1 (1. Graduate School of Engineering Science, Osaka University, 2. Center for Mesoscopic Sciences, Institute for Molecular Science)
Vanadium dioxide (VO2) thin films exhibit a metal–insulator transition (MIT) with a resistance change of three orders of magnitude around 67 ℃, transitioning from a semiconducting monoclinic (M1) phase to a metallic tetragonal rutile (R) phase. Studying the transition dynamics between these phases in real space with high resolution is challenging. In this study, we grew VO2 thin films on TiO2(110) substrates to investigate their crystallinity and MIT dynamics using operando XRD and s-SNOM. XRD results show a significant shift in the VO2(220) diffraction peak, indicating the structural transition. s-SNOM measurements resolve the MIT dynamics using infrared nanoimaging, distinguishing the phases through contrasted scattering amplitudes at the nanoscale. Our findings enhance understanding of MIT dynamics, shedding light on the initial site of MIT, the spread of metallic domains, and visualizing nanoscale MIT dynamics in real space.