Affiliations: Department of Electronic and Computer Engineering, Tokyo Denki University, Ishizaka, Hatoyama, Hiki, Saitama, 350‐0394, Japan Tel: +81 492 96 2911(3155); Fax: +81 492 96 6413; E‐mail: ozeki@bme.f.dendai.ac.jp | Tokyo Bioceramics Institute Co. Ltd., Kyodo Bldg, 1‐9‐12, Nihonbashi Muromachi, Chuo‐Ku, Tokyo, 103‐0022, Japan | Department of Biomedical Engineering, Hokkaido University, Kita‐13 Nishi‐8, Kita‐ku, Sapporo, 060‐8628, Japan
Abstract: Crystalline hydroxyapatite (HA) powder was coated on titanium substrate by radio frequency (RF) magnetron sputtering. The coating was homogeneous thin film and the thickness was 1μm. Crystallinity of the HA coating was low and Ca/P ratio was high as 3.0. Particle sizes were 40∼100 nm, and the crystallite size was calculated by 30∼50 nm using an X‐ray diffractometry (XRD) and a transmission electron microscopy (TEM). When the coating was heated at 800○C for 1 h, the low crystalline HA grew up crystalline HA, and a diffraction pattern of CaO appeared. When the coating was immersed in pH 7.4 of bovine serum for 1 week, c‐axis of HA increased.
