Angle-resolved photoemission spectroscopy for VO 2 thin films grown on TiO 2 (0 0 1) substrates

Abstract

We present the results of angle-resolved photoemission spectroscopy (ARPES) measurements of metallic VO 2 thin films. The VO 2 thin films have been grown on TiO 2 (0 0 1) single crystal substrates using pulsed laser deposition. The films exhibit a first-order metal–insulator transition (MIT) at 305 K. In the ARPES spectra of the metallic phase for the films, the O 2 p band shows highly dispersive feature in the binding energy range of 3–8 eV along the Г– Z direction. The periodicity of the dispersive band is found to be 2.2 Å −1 which is almost identical with the periodicity expected from the c-axis length of the VO 2 thin films. The overall feature of the experimental band structure is similar to the band structure calculations, supporting that we have succeeded in observing the dispersive band of the O 2 p state in the metallic VO 2 thin film. The present work indicates that the ARPES measurements using epitaxial thin films are promising for determining the band structure of VO 2.