Abstract: Hydroxyapatite (HA) thin films were deposited onto titanium substrates separately by ion beam sputtering (IBS) and ion beam enhanced deposition (IBED) methods, by using
sintered pure HA ceramic as a target material. X-ray photoelectron spectroscopy (XPS) analysis showed that the chemical states of Ca, P, O elements of the deposited films
were close to those of used HA ceramic target. The existence of CO^2-₃ was also determined in the deposited films. The as-deposited films both achieved by IBS and IBED
methods were amorphous, and a hydroxyapatite -type structure was achieved from the annealed films, as revealed by X-ray diffraction analysis. After immersion in the stimulated
body fluid (SBF), the as-deposited films dissolved easily. XPS analysis showed that the deposited films experienced only Ca, P and O ion exchange with the SBF, and the reprecipitation
of calcium phosphate on the deposited films was determined. In comparison with the IBS films, the formation of calcium phosphate was accelerated for the IBED films.

Key words: hydroxyapatite film, titanium, ion beam technique, structural analysis, solubility