In this work, we investigate the structural properties and, in particular, the residual stress of carbon-implanted TiN coatings by means of glancing incidence X-ray diffraction and secondary ion mass spectrometry techniques. The coatings were grown by ion-beam physical vapor deposition on steel substrates and subsequently implanted at 100 keV with carbon doses of 1 × 1017, 3 × 1017 and 7 × 1017 ions/cm2. The carbon depth profiles obtained by secondary ion mass spectrometry enable us to choose the more appropriate X-ray beam incidence angles in order to detect the structural variations in proximity to the implanted region. The X-ray results indicate notable variations both in the crystallinity and in the residual stress and such modifications depend on the carbon dose and penetration depth. In particular, in the coating implanted with a dose of 1 × 1017 ions/cm2 the initial compressive residual stress is reduced until a penetration depth of at least 400 nm. In addition, the lattice is re-crystallized in the first 100 nm. The coatings implanted with doses of 3 × 1017 and 7 × 1017 ions/cm2 have a surface region (100 nm thick) in the tensile stress state and a peak of compressive stress well above the non-implanted value at a depth between Rp and 2Rp. Moreover, the effect of C+ implantation is to reduce the lattice parameters for all the investigated samples. Such results can be explained by considering the defect distribution induced by the implantation process and the competition between the implantation amorphization and the self-annealing behavior. © 2001 Elsevier Science B.V.

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