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Title: Structure of multilayered Cr(Al)N/SiO{sub x} nanocomposite coatings fabricated by differential pumping co-sputtering

A Cr(Al)N/38 vol. % SiO{sub x} hard coating was prepared on a (001) Si substrate at 250 °C in a differential pumping co-sputtering system, which has two chambers for radio frequency (RF) sputtering and a substrate holder rotating on the chambers. The composite coating was grown by alternate sputter-depositions from CrAl and SiO{sub 2} targets with flows of N{sub 2}+Ar and Ar at RF powers of 200 and 75 W, respectively, on transition layers grown on the substrate. Analytical electron microscopy reveled that the Cr(Al)N/SiO{sub x} coating had a multilayered structure of Cr(Al)N crystal layers ∼1.6 nm thick and two-dimensionally dispersed amorphous silicon oxide (a-SiO{sub x}) particles with sizes of ∼1 nm or less. The a-SiO{sub x} particles were enclosed with the Cr(Al)N layers. The coating had a low indentation hardness of ∼25 GPa at room temperature, due to a high oxide fraction of 38 vol. % and a low substrate rotational speed of 1 rpm. Faster rotation and lower oxide fraction would make a-SiO{sub x} particles smaller, resulting in the formation of Cr(Al)N crystal including the very fine a-SiO{sub x} particles with small number density. They would work as obstacles for the lattice deformation of the Cr(Al)N crystals. Wemore » have fabricated a superhard coating of Cr(Al)N/17 vol. % SiO{sub x} with a hardness of 46 GPa prepared at 12 rpm.« less
Authors:
 [1] ;  [2] ;  [3] ;  [4]
  1. JEOL USA Inc., 11 Dearborn Road, Peabody, Massachusetts 01960 (United States)
  2. Faculty of Art and Design, University of Toyama, 180 Futagami-machi, Takaoka 933-8588 (Japan)
  3. JEOL Ltd. 3-1-2 Musashino, Akishima, Tokyo 196-8558 (Japan)
  4. Kyoto Institute of Technology, Kyoto 606-8585 (Japan)
Publication Date:
OSTI Identifier:
22217807
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 103; Journal Issue: 20; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; COATINGS; CRYSTALS; DEFORMATION; ELECTRON MICROSCOPY; HARDNESS; LAYERS; NANOSTRUCTURES; NITROGEN 17; PARTICLES; PRESSURE RANGE GIGA PA; PUMPING; RADIOWAVE RADIATION; SILICA; SILICON OXIDES; SPUTTERING; SUBSTRATES; SURFACE COATING; TEMPERATURE RANGE 0273-0400 K