Back

Title
  • en Thermopower analysis of metal-insulator transition temperature modulations in vanadium dioxide thin films with lattice distortion
Creator
    • en Katase, Takayoshi
    • en Endo, Kenji
Accessrights open access
Rights
  • en ©2015 American Physical Society
Subject
  • NDC 420
Description
  • Abstract en Insulator-to-metal (MI) phase transition in vanadium dioxide (VO2) thin films with controlled lattice distortion was investigated by thermopower measurements. VO2 epitaxial films with different crystallographic orientations, grown on (0001) alpha-Al2O3, (11 (2) over bar0) alpha-Al2O3, and (001) TiO2 substrates, showed significant decrease of absolute value of Seebeck coefficient (S) from similar to 200 to 23 mu VK-1, along with a sharp drop in electrical resistivity (rho), due to the transition from an insulator to a metal. The MI transition temperatures observed both in rho(T-rho) and S(T-S) for the VO2 films systematically decrease with lattice shrinkage in the pseudorutile structure along the c axis, accompanying a broadening of the MI transition temperature width. Moreover, the onset T-S, where the insulating phase starts to become metallic, is much lower than the onset T-rho. This difference is attributed to the sensitivity of S for the detection of hidden metallic domains in the majority insulating phase, which cannot be detected in rho measurements. Consequently, S measurements provide a straightforward and excellent approach for a deeper understanding of the MI transition process in VO2.
Publisher en American Physical Society
Date
    Issued2015-07-13
Language
  • eng
Resource Type journal article
Version Type VoR
Identifier HDL http://hdl.handle.net/2115/59763
Relation
  • isIdenticalTo DOI https://doi.org/10.1103/PhysRevB.92.035302
Journal
    • PISSN 1098-0121
      • en Physical review B
      • Volume Number92 Issue Number3 Page Start35302-1 Page End35302-7
File
Oaidate 2023-07-26