Chemical State of Nitrogen in Nitrogen-Doped Hydroxyapatite Ceramics with Enhanced Bioactivity

Abstract

The chemical state of nitrogen which was induced into crystal structure of hydroxyapatite by nitrogen-doping method (N-doping method) was examined. Determination of lattice constants by powder X-ray diffraction (XRD) showed that the nitrogen species induced by N-doping method substituted the OH- ion in the crystal structure of hydroxyapatite. In addition, Fourier transform infrared spectroscopy (FT-IR) and temperature programmed desorption-mass spectroscopy (TPD-MS) determined that the chemical state of nitrogen induced by N-doping method was N2O.