抄録
Non-stoichiometric hydroxyapatite (HAp) microcrystals other than amorphous calcium phosphate (ACP) were directly formed at high pH region. The HAp was precipitated by adding phosphoric acid solution to calcium hydroxide aqueous suspension in room temperature with vigorous stirring. The products at pH 13 consisted of HAp microcrystals as well as calcium hydroxide. The most intense XRD peak of HAp was unified reflection of 211 and 112 although it was separated from 300 reflection. The position of strongest peak was shifted compared with that of ACP. Topotaxial relationships between the HAp and calcium hydroxide were revealed by electron diffractometry. It was suggested that the HAp microcrystals were not obtained by simple depositional reaction from aqueous solution.
