Deposition of hydroxyapatite thin films from saturated calcium phosphate solution by controlling the substrate temperature

The solubility of calcium phosphate aqueous solution decreases with increasing temperature. In this investigation, hydroxyapatite (HAp) thin films were deposited on the various substrates applying this calcium phosphate solubility depending on the solution temperature, the solution temperature was kept at 10°C and the substrate temperature was kept about 80°C. HAp thin film with a single phase was deposited on Si wafer and metal Ti substrates. HAp and β-tricalcium phosphate mixture phase was observed for the film on YSZ substrates. All the resulting films were very dense, and the deposition rates of the films on all the substrates were 10–15 nm/min.