Apatite Deposition on ZrO_2 Thin Films by DC Unbalanced Magnetron Sputtering

摘要

Zirconia thin films deposited on 316L stainless-steel substrate were prepared by DC unbalanced magnetron sputtering from a metallic zirconium target at low temperature with the target-to-substrate distance (d_(t-s)) of 100 mm and sputtering power of 180 W. High purity gas of Ar as the working gas and O_2 as the reactive gas were used. The depositions were performed for 120 min at a total pressure of 0.5 Pa. The effect of thermal treatment on the HA formation was investigated. The bioactivity was assessed by investigating the formation of hydroxyapatite (HA) on the surface soaked in simulated body fluids (SBF). Films structure, surface morphology and chemical composition of the ZrO_2 films and HA formation were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and FT-IR spectroscopy. The XRD results demonstrate the ZrO_2 films are monoclinic phase. The annealed films show the higher film crystalline due to the rearrangement of film structure. After being immersed the samples in SBF, the bone-like apatite was observed on all ZrO_2 films, but a denser and more continuous HA layer were observed on annealed films due to the crystallinity of ZrO_2 films.