Preparation of Ca-Ti-O/Ca-P-O Functionally Graded Bio-ceramic Film by MOCVD

Abstract

Ca-Ti-O and Ca-P-O films were prepared by MOCVD. The phases, composition and morphology of Ca-Ti-O and Ca-P-O films changed depending on the molar ratio of Ca to Ti (R_Ca/Ti) and Ca to P (R_Ca/P) precursors, total pressure (P_tot) and substrate temperature (T_sub). CaTiO₃ films in a single phase were obtained at T_sub=973 and 1073 K. CaTiO₃ films prepared at T_sub=873 K had a dense and smooth surface. CaTiO₃ films prepared at T_sub=1073 K had complicated rough surface with a cauliflower-like texture. α-TCP and HAp films in a single phase were obtained at T_sub=973 and 1073 K, and both films had dense microstructure. Apatite formed after 3 days on the CaTiO₃ film, while 14 days on the α-TCP film and 6 hours on the HAp film, respectively. Functionally graded Ca-Ti-O/Ca-P-O films were successfully prepared by MOCVD, and expected to have good bone conductivity and adherence to Ti substrate.