Structure and Solubility of Hydroxyapatite Thin Films Produced by Ion Beam Technique

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) ajnalysis showedthat the chemical states of Ca, P, O elements of the deposited films were close to those of usedHA ceramic target. The existence of was also determined in the deposited films. The asdeposited 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. XPSanalysis showed that the deposited films experienced only Ca, P and O ion exchange with theSBF, and the reprecipitation of calcium phosphate on the deposited films was determined. Incomparison with the IBS films, the formation of calcium phosphate was accelerated for the IBED films.