Transmission Electron Microscopic Study on Thermal Decomposition Process of Calcium-Deficient Hydrqxyapatite

摘要

In our previous study, we reported that a metastable phase with high Ca/P molar ratio appeared in the temperature range from 700 deg C to 800 deg C. The purpose of this study is to investigate the crystallographic relationship between the metastable phase and HAp matrix. Ca-def HAp was annealed at 500-1000 deg C in air. High-resolution transmission electron microscopic (HRTEM) observations were performed along the [010], [110] and [001] zone axes in order to investigate the structure of the metastable phase. From HRTEM images and results of the analysis of selected area electron diffraction patterns along [010], [110] and [001] zone axes, the lattice constants of the metastable phase were analyzed into a=2.86nm, b=0.94nm, and c=0.69nm of an orthorhombic crystals system.