Metal-insulator transition of monoclinic VO2 thin film without Peierls distortion

Abstract

Abstract VO2 thin film with a metal-insulator transition (MIT) temperature of about 37\u202f°C was fabricated on the 300\u202f°C indium-tin oxide substrates, in which the evident lattice distortion was seen because the 2θ value of the as-deposited film was even smaller than that of the standard VO2(R) (110) plane. Transmission electron microscopy demonstrated that the crystal structure of the as-deposited film was VO2(M) rather than VO2(R). In-situ x-ray diffraction at varied temperatures revealed that the crystal structure transition was suppressed with the temperature increasing, indicating that MIT was only driven by the electron-electron correlations. The experimental result was further verified by the density functional theory calculations, proving the presence of the monoclinic metal phase for the first time.