Precipitation Behavior in a Hanks’ Solution on Ca-P-O Films Prepared by Laser CVD

Abstract

Ca-P-O films were prepared by laser CVD using Ca(dpm) 2 and (C 6 H 5 O) 3 PO metal organic precursors. The crystal phase of Ca-P-O films changed depending on deposition temperature (T dep ), total pressure (P tot ), laser power (P L ) and molar ratio of Ca to P (R Ca/P ). -TCP films in a single phase were obtained in a P-rich and high T dep region, while HAp films in a single phase were obtained in a Ca-rich and low T dep region. The -TCP films had a (220) orientation with an elongated and angular roof-shaped surface texture, whereas HAp films had a (300) orientation with a granular surface texture. Both the -TCP film and the HAp film had a dense cross section. The Ca-P-O films were immersed in a Hanks' solution for 6 h to 7 d. Particle-shaped precipitates were observed on the -TCP and HAp films after 3 d immersion. Needle-shaped precipitates covered the whole surface of HAp film after 7 d immersion.

Chemical Vapor Deposition of Ca–P–O Film Coating

“…Figure 9.10a, b depict the relationship between deposition parameters and the crystal phases (CVD phase diagram) by LCVD using Ca(dpm) 2 and (C 6 H 5 O 3 )PO as source gases at a low (30 W) and high (200 W) laser power, respectively [28]. At relatively low T dep of 750-950 K. a mixture film of OAp and β-TCP or OAp and TTCP can be obtained under a wide range of conditions.…”