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Title: Effect of oxygen incorporation on the structure and elasticity of Ti-Al-O-N coatings synthesized by cathodic arc and high power pulsed magnetron sputtering

Ti-Al-O-N coatings were synthesized by cathodic arc and high power pulsed magnetron sputtering. The chemical composition of the coatings was determined by means of elastic recoil detection analysis and energy dispersive X-ray spectroscopy. The effect of oxygen incorporation on the stress-free lattice parameters and Young's moduli of Ti-Al-O-N coatings was investigated by X-ray diffraction and nanoindentation, respectively. As nitrogen is substituted by oxygen, implications for the charge balance may be expected. A reduction in equilibrium volume with increasing O concentration is identified by X-ray diffraction and density functional theory calculations of Ti-Al-O-N supercells reveal the concomitant formation of metal vacancies. Hence, the oxygen incorporation-induced formation of metal vacancies enables charge balancing. Furthermore, nanoindentation experiments reveal a decrease in elastic modulus with increasing O concentration. Based on ab initio data, two causes can be identified for this: First, the metal vacancy-induced reduction in elasticity; and second, the formation of, compared to the corresponding metal nitride bonds, relatively weak Ti-O and Al-O bonds.
Authors:
; ; ; ;  [1] ;  [2] ; ; ;  [3]
  1. Materials Chemistry, RWTH Aachen University, Kopernikusstr. 10, D-52074 Aachen (Germany)
  2. Department of Physics and Astronomy, Uppsala University, Lägerhyddsvägen 1, S-75120 Uppsala (Sweden)
  3. Oerlikon Balzers Coating AG, Iramali 18, LI-9496 Balzers, Principality of Liechtenstein (Liechtenstein)
Publication Date:
OSTI Identifier:
22314382
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 116; Journal Issue: 9; Other Information: (c) 2014 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; COATINGS; CONCENTRATION RATIO; DENSITY FUNCTIONAL METHOD; ELASTICITY; LATTICE PARAMETERS; MAGNETRONS; METALS; OXYGEN; PULSES; SPUTTERING; STRESSES; VACANCIES; X-RAY DIFFRACTION; X-RAY SPECTROSCOPY