Phase formation in titanium after high-fluence oxygen ion implantation

Oxygen ions were implanted with an energy of 180 keV and doses between 1.10 (17) O+/cm(2) and 15.10(17) O+/cm(2) into titanium at temperatures lower th an -20 degrees C. The chemical composition was investigated using Rutherfor d Backscattering Spectrometry and Elastic Recoil Detection Analysis and the concentration profiles were calculated by using TRIDYN computer simulation s. The oxygen distribution reveals a Gaussian-like shape which confirms the absence of diffusion at temperatures lower than -20 degrees C. The study o f phase formation as a function of the implantation dose and the morphology was studied by synchrotron X-ray diffraction and cross section transmissio n electron microscopy, respectively. The existence of alpha- and beta-TiO, Rutile TiO2, delta-TiO, and Anosovite Ti3O5 after implantation was demonstr ated and is discussed in connection with lattice invariant deformations and simple lattice transformations. (C) 1999 Elsevier Science B.V. All rights reserved.