AVS 58th Annual International Symposium and Exhibition
    Advanced Surface Engineering Division Thursday Sessions
       Session SE-ThM

Paper SE-ThM11
Tuning the Properties of Chromium Oxynitride Coatings

Thursday, November 3, 2011, 11:20 am, Room 104

Session: Nanostructured Thin Films and Coatings
Presenter: Joerg Patscheider, EMPA, Switzerland
Authors: L. Castaldi, Oerlikon Balzers AG, Liechtenstein
J. Patscheider, EMPA, Switzerland
V. Shklover, ETH Zurich, Switzerland
D. Kurapov, Oerlikon Balzers AG, Liechtenstein
A. Reiter, Oerlikon Balzers AG, Liechtenstein
Correspondent: Click to Email
CrOxN1-x coatings deposited by reactive cathodic arc evaporation were investigated for concentration levels oxygen between 0 and 1. The present study shows some of the possibilities for tuning the crystallographic and electronic properties of chromium oxynitride films by progressively increasing the oxygen concentration. Upon oxygen addition the CrOxN1-x films remain in the face-centered cubic B1 structure of CrN for oxygen fractions of up to x = 0.70. At higher oxygen contents the properties of the films approach those of Cr2O3 and crystallize in the corundum structure. The gradual decrease of the stress-free lattice parameter of the films with the B1 structure at higher oxygen concentrations is consistent with oxygen substituting progressively nitrogen atoms. The almost random orientation of oxygen-free CrN films transforms to a distinct (001) preferred orientation with the increase of oxygen concentration in the films. XPS investigations prove enhanced charge transfer from Cr to O 1s with increasing x with respect to N by changes in the core-level binding energies (BE) of the Cr 2p3/2 and N. A shift of the valence band edge toward higher BE indicates a decrease of electrical conductivity of the films with increasing oxygen content.