NOVEL CHROMIUM LAYERS FORMED BY NITROGEN-ION IMPLANTATION OF CONVENTIONAL AND ABCD ELECTRODEPOSITED FILMS .4.

Nitrogen‐ion implantation of conventional Cr and amorphous bright chromium‐deposited (ABCD) films which were preannealed at various temperatures, has been carried out in order to determine the effect of implantation on the hardness of the Cr layers. The implantation was carried out using low ion beam fluxes in order to maintain a sample temperature below 250°C. Implantation leads to increased hardness, but the extent is most pronounced for conventional films which were not annealed and ABCD films which were annealed at or below 400°C for ½ h. The surface sensitivity of the hardness measurements was varied by altering the load used during the test. Data obtained in this manner show that the more surface‐sensitive hardness is greater than the more bulk‐sensitive hardness for both the implanted and non‐implanted ABCD films and the implanted conventional Cr films. The compositions of the implanted films have been characterized using Auger electron spectroscopy in conjunction with sputter depth profiling. These data show that all of the Cr in the implanted region is bound as CrN, Cr oxides and Cr carbides at large total N+ doses. Furthermore, the N displaces the C in ABCD films producing N and C profiles that mimic each other in an inverse manner. Copyright © 1990 John Wiley & Sons Ltd.