TEM Examinations of OCP/HA Transformation
We have directly observed the transformation from octacalcium phosphate (OCP) to hydroxyapatite (HA) in transmission electron microscope (TEM). The phase transformation was induced by electron beam irradiation in TEM. Several TEM techniques were employed to examine the crystal structure change, including bright field images, electron diffraction, high resolution microscopy (HRTEM) and fast Fourier transformation pattern of HRTEM images. The examinations indicate possible hydrolysis reaction in solid state transformation and crystallographic orientation of OCP (010)//HA (010) and OCP (001)//HA (001) which has not been reported previously.
Takashi Nakamura, Kimihiro Yamashita and Masashi Neo
R. L. Xin et al., "TEM Examinations of OCP/HA Transformation", Key Engineering Materials, Vols. 309-311, pp. 191-194, 2006