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Title: Semiconductor-insulator transition in VO{sub 2} (B) thin films grown by pulsed laser deposition

Thin films of B-phase VO{sub 2} were grown by pulsed-laser deposition on glass and (100)-cut MgO substrates in a temperature range from 375 to 425 °C and at higher gas pressures than usual for this technique. The films were strongly oriented, with ab-planes parallel to the substrate surface. Detailed study of surface morphology through Atomic Force Microscopy images suggest significant differences in evolution as a function of growth temperature for films on the two types of substrates. Measurements of electrical conductivities through cooling-heating cycles from room temperature to 120 K showed changes of five orders of magnitude, with steeper changes between room temperature and ∼150 K, which corresponds with the extended and reversible phase transition known to occur for this material. At lower temperatures conductivities exhibited Arrhenius behavior, indicating that no further structural change was occurring and that conduction is thermally activated. In this lower temperature range, conductivity of the samples can be described by the near-neighbor hopping model. No hysteresis was found between the cooling and heating braches of the cycles, which is at variance with previous results published for VO{sub 2} (B). This apparent lack of hysteresis for thin films grown in the manner described and the large conductivity variation asmore » a function of temperature observed for the samples suggests this material could be of interest for infrared sensing applications.« less
Authors:
; ; ;  [1]
  1. Department of Physics, University of Puerto Rico, Mayagüez, Puerto Rico 00681-9000 (United States)
Publication Date:
OSTI Identifier:
22492751
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 118; Journal Issue: 12; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ATOMIC FORCE MICROSCOPY; ELECTRIC CONDUCTIVITY; ENERGY BEAM DEPOSITION; LASER RADIATION; MAGNESIUM OXIDES; PHASE TRANSFORMATIONS; SEMICONDUCTOR MATERIALS; TEMPERATURE DEPENDENCE; TEMPERATURE RANGE 0273-0400 K; THIN FILMS; VANADIUM OXIDES