Ion-beam-sputtering/mixing deposition of calcium phosphate coatings. I. Effects of ion-mixing beams

Ion-beam-sputtering/mixing deposition was used to produce thin calcium phosphate coatings on titanium substrate from the hydroxyapatite target. The mixing beam could be either Ar(+) or N(+) ions. It was found that as-deposited coatings were amorphous. No distinct peak of the hydroxyl group was observed in FTIR spectra of the coatings, but new spectral peaks, brought about during the deposition process, were present for CO(3)(2-). Scanning electron microscopy revealed that the deposited coatings had a uniform and dense structure. The calcium-to-phosphorous ratio of these coatings varied between 2.0 and 3.0. Compared with the calcium phosphate coatings produced by Ar(+) beam-mixing deposition, the calcium phosphate coatings produced by N(+) beam-mixing deposition exhibited a higher dissolution rate in the physiologic saline solution and showed a lower proliferation rate of osteoblast cells.