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Title: On the thermal stability of physical vapor deposited oxide-hardened nanocrystalline gold thin films

We describe a correlation between electrical resistivity and grain size for PVD synthesized polycrystalline oxide-hardened metal-matrix thin films in oxide-dilute (<5 vol. % oxide phase) compositions. The correlation is based on the Mayadas-Shatzkes (M-S) electron scattering model, predictive of grain size evolution as a function of composition in the oxide-dilute regime for 2 μm thick Au-ZnO films. We describe a technique to investigate grain boundary (GB) mobility and the thermal stability of GBs based on in situ electrical resistivity measurements during annealing experiments, interpreted using a combination of the M-S model and the Michels et al. model describing solute drag stabilized grain growth kinetics. Using this technique, activation energy and pre-exponential Arrhenius parameter values of E{sub a} = 21.6 kJ/mol and A{sub o} = 2.3 × 10{sup −17} m{sup 2}/s for Au-1 vol. % ZnO and E{sub a} = 12.7 kJ/mol and A{sub o} = 3.1 × 10{sup −18} m{sup 2}/s for Au-2 vol. % ZnO were determined. In the oxide-dilute regime, the grain size reduction of the Au matrix yielded a maximum hardness of 2.6 GPa for 5 vol. % ZnO. A combined model including percolation behavior and grain refinement is presented that accurately describes the composition dependent change in electrical resistivity throughout the entire composition range for Au-ZnO thin films. The proposed correlations aremore » supported by microstructural characterization using transmission electron microscopy and electron diffraction mapping for grain size determination.« less
Authors:
; ; ; ; ; ; ;  [1]
  1. Materials Science and Engineering Center, Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)
Publication Date:
OSTI Identifier:
22402849
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 117; Journal Issue: 14; Other Information: (c) 2015 U.S. Government; 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; ACTIVATION ENERGY; ANNEALING; CORRELATIONS; ELECTRIC CONDUCTIVITY; ELECTRON DIFFRACTION; ELECTRONS; GOLD; GRAIN BOUNDARIES; GRAIN GROWTH; GRAIN REFINEMENT; GRAIN SIZE; HARDNESS; NANOSTRUCTURES; PHYSICAL VAPOR DEPOSITION; POLYCRYSTALS; THIN FILMS; TRANSMISSION ELECTRON MICROSCOPY; VAPOR DEPOSITED COATINGS; ZINC OXIDES