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Title: Macro- and microscopic properties of strontium doped indium oxide

Solid state synthesis and physical mechanisms of electrical conductivity variation in polycrystalline, strontium doped indium oxide In{sub 2}O{sub 3}:(SrO){sub x} were investigated for materials with different doping levels at different temperatures (T = 20–300 °C) and ambient atmosphere content including humidity and low pressure. Gas sensing ability of these compounds as well as the sample resistance appeared to increase by 4 and 8 orders of the magnitude, respectively, with the doping level increase from zero up to x = 10%. The conductance variation due to doping is explained by two mechanisms: acceptor-like electrical activity of Sr as a point defect and appearance of an additional phase of SrIn{sub 2}O{sub 4}. An unusual property of high level (x = 10%) doped samples is a possibility of extraordinarily large and fast oxygen exchange with ambient atmosphere at not very high temperatures (100–200 °C). This peculiarity is explained by friable structure of crystallite surface. Friable structure provides relatively fast transition of samples from high to low resistive state at the expense of high conductance of the near surface layer of the grains. Microscopic study of the electro-diffusion process at the surface of oxygen deficient samples allowed estimation of the diffusion coefficient of oxygen vacancies in the friable surface layer at roommore » temperature as 3 × 10{sup −13} cm{sup 2}/s, which is by one order of the magnitude smaller than that known for amorphous indium oxide films.« less
Authors:
; ; ;  [1] ; ; ; ; ;  [2]
  1. Donetsk Institute for Physics and Technology, National Academy of Sciences of Ukraine, 83114 Donetsk (Ukraine)
  2. Institute of Materials Science, Darmstadt University of Technology, 64287 Darmstadt (Germany)
Publication Date:
OSTI Identifier:
22308531
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 116; Journal Issue: 4; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ATMOSPHERES; DIFFUSION; DOPED MATERIALS; ELECTRIC CONDUCTIVITY; FILMS; HUMIDITY; INDIUM OXIDES; LAYERS; OXYGEN; POLYCRYSTALS; SOLIDS; STRONTIUM ADDITIONS; STRONTIUM OXIDES; SURFACES; SYNTHESIS; TEMPERATURE RANGE 0273-0400 K; TEMPERATURE RANGE 0400-1000 K; VACANCIES