Calcium phosphate targets for RF magnetron sputtering of biocoatings

Abstract

The surface modification of implants became of vital importance for medical field. One of the promising techniques allowing to deposit biocoatings with tailored properties including antibacterial activity is an RF magnetron sputtering. The material of the sputtering target that is going to be deposited on the surface of an implant can be made from various calcium phosphates. Here we present the results of Zn- and Cu-substituted hydroxyapatites and pure hydroxyapatite materials synthesised by mechanochemical method that were sintered in the form of targets for subsequent RF magnetron sputtering. With a set of analytical methods and physico-mechanical testing including X-ray diffraction analysis, energy-dispersive spectroscopy, microhardness measurements and the texture analysis it was shown that the approaches and regimes described in the paper allowed us to produce targets with desired phase composition and good mechanical properties. We estimated the influence of specific surface area of initial calcium phosphate powder with various hydroxyapatite compositions on sintered targets' microhardness. It is concluded that the use of powders with specific surface area in the range of 40-60 m2/g is beneficial for formation and sintering of targets with high physico-mechanical parameters.