skip to main content

Title: Collapse of the low temperature insulating state in Cr-doped V{sub 2}O{sub 3} thin films

We have grown epitaxial Cr-doped V{sub 2}O{sub 3} thin films with Cr concentrations between 0% and 20% on (0001)-Al{sub 2}O{sub 3} by oxygen-assisted molecular beam epitaxy. For the highly doped samples (>3%), a regular and monotonous increase of the resistance with decreasing temperature is measured. Strikingly, in the low doping samples (between 1% and 3%), a collapse of the insulating state is observed with a reduction of the low temperature resistivity by up to 5 orders of magnitude. A vacuum annealing at high temperature of the films recovers the low temperature insulating state for doping levels below 3% and increases the room temperature resistivity towards the values of Cr-doped V{sub 2}O{sub 3} single crystals. It is well-know that oxygen excess stabilizes a metallic state in V{sub 2}O{sub 3} single crystals. Hence, we propose that Cr doping promotes oxygen excess in our films during deposition, leading to the collapse of the low temperature insulating state at low Cr concentrations. These results suggest that slightly Cr-doped V{sub 2}O{sub 3} films can be interesting candidates for field effect devices.
Authors:
; ; ; ; ; ; ; ;  [1] ; ; ;  [2] ;  [3]
  1. Department of Physics and Astronomy, KU Leuven, Celestijnenlaan 200D, 3001 Leuven (Belgium)
  2. Department of Physics, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium)
  3. Department of Materials Engineering, KU Leuven, Kasteelpark Arenberg 44, 3001 Leuven (Belgium)
Publication Date:
OSTI Identifier:
22482077
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 107; Journal Issue: 11; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ALUMINIUM OXIDES; DEPOSITION; DOPED MATERIALS; MOLECULAR BEAM EPITAXY; MONOCRYSTALS; OXYGEN; THIN FILMS; VANADIUM OXIDES