Reactive Plasma-Aided RF Sputtering Deposition of Hydroxyapatite Bio-implant Coatings


  • The authors thank A. E. Rider for fruitful discussions. This work was supported by A*STAR (Singapore), the Australian Research Council, the University of Sydney, and the International Research Network for Deterministic Plasma-Aided Nanofabrication.


The plasma-assisted RF sputtering deposition of a biocompatible, functionally graded calcium phosphate bioceramic on a Ti6Al4 V orthopedic alloy is reported. The chemical composition and presence of hydroxyapatite (HA), CaTiO3, and CaO mineral phases can be effectively controlled by the process parameters. At higher DC biases, the ratio [Ca]/[P] and the amount of CaO increase, whereas the HA content decreases. Optical emission spectroscopy suggests that CaO+ is the dominant species that responds to negative DC bias and controls calcium content. Biocompatibility tests in simulated body fluid confirm a positive biomimetic response evidenced by in-growth of an apatite layer after 24 h of immersion.