X-Ray Diffractometry and X-Ray Photoelectron Spectroscopy Investigations of Nanocrytalline Hydroxyapatite Synthesized by a Hydroxide Gel Technique : Structure and Mechanical and Thermal Properties of Condensed Matter

概要

論文の詳細を見る
Nanocrystalline hydroxyapatite (HA), Ca_<10>(PO_4)_6(OH)_2, has been synthesized by a precipitate-conversion technique using hydroxide gel. Hydroxyapatite crystallizes in a hexagonal structure (space group; P6_<3/m>) having lattice parameters; a = 9.407A and c = 6.883A, and around 37nm in size for the 800℃-annealed sample. Substantial crystalline characteristics are observed for the material heat-treated at 80℃. With the increase of air-annealing temperature, from 80℃ to 800℃, lattice expansion along all crystallographic axes occurs indicating a structural change in the HA lattice. These results have been attributed to (1) the formation of a relative Ca^<2+> deficiency in HA that incorporates various chemical species in the anionic sites compared to their lower temperature air-annealed counterparts, and (2) the precipitation of CaO with increasing air-annealing temperature. The X-ray photoelectron spectroscopy studies indicate a distorted anionic structure and two electronic states for the O1s, corroborating the observed X-ray diffraction results.
社団法人応用物理学会の論文
2001-08-15