Fig. 1.
Surface characterizations of various samples. (a) SEM images of the surface morphologies of various samples at low and high magnifications (i, ii, ii, and iv present Ti, Zn-Ti, Cu-Ti, and Ag-Ti, respectively). (b) AFM images of (i, ii, ii, and iv) two-dimensional morphologies, (v, vi, vii, and vii) three-dimensional morphologies, and (ix, x, xi, and xii) the depth profiles of different samples (i, v, and ix present Ti; ii, vi, and x present Zn-Ti; ii, vii and xi present Cu-Ti; iv, vii and xii present Ag-Ti). (c) XPS spectra of the Zn-Ti, Cu-Ti, and Ag-Ti samples. (d) The concentrations of implanted ions in PBS solution after immersion for 1, 4, 7, 14, 21, and 28 d.