Apatite formation behavior on bio-ceramic films prepared by MOCVD

Abstract

Calcium titanate (CaTiO3), α-tricalcium phosphate (α-TCP) and hydroxyapatite (HAp) films were prepared by metal-organic chemical vapor deposition (MOCVD) using Ca(dpm)2, Ti(O-i-Pr) 2(dpm)2 and (C6H5O)3PO precursors. The phases, composition and surface morphology of these films changed depending on substrate temperature (Tsub), total pressure (Ptot) and molar ratio of each precursors (RCa/Ti, R Ca/P). The surface morphology of CaTiO3 films changed from granular structure to cauliflower-like texture, and its cross-sectional morphology changed from dense to columnar structure with increasing T sub. α-TCP and HAp films had granular surface and dense cross-sectional morphology. CaTiO3, α-TCP and HAp films were immersed in a Hanks' solution for 28 d. Apatite formation rate strongly depended on the surface morphology of CaTiO3 film, and apatite covered CaTiO3 film having a granular surface after 4 w while CaTiO 3 film having a cauliflower-like texture after 3 d. Apatite covered α-TCP films after 14 d and HAp films after 6 h, respectively. HAp films prepared by MOCVD were promising as bone conductive materials. © 2009 The Ceramic Society of Japan.