1992 Volume 43 Issue 12 Pages 1216-1222
Polycrystalline chromium metal plates (purity>99.99%) were implanted with nitrogen ions (N2+) at energies of 500keV, 1MeV, 1.5MeV and 2MeV and the doses of from 3×1017 to 1×1018N atoms/cm2. The implanted chromium plates were annealed repeatedly at varying temperatures from 250°C to 800°C. The depth profiles of nitrogen concentration was investigated by Rutherford Backscattering Spectrometry (RBS) and the crystallinity of the nitride layer was studied by XRD. At temperatures up to 400-500°C, CrN converted to Cr2N and phase transition were observed. However, the amorphous nature of the nitride layer formed was kept after annealing. The maximum Cr2N layer thickness of obtained by multiple implantation (2MeV-1.5MeV-1MeV, total=2.1·1018) and subsequent annealing was 650nm (from 200nm to 850nm in depth scale).
