Abstract—In present study, X-ray peak profile analysis (XPPA) by modified Williamson-Hall (W-H) models, namely W-H-isotropic strain model (W-H-ISM), W-H-anisotropic strain model (W-H-ASM) and W-H-energy density model (W-H-EDM), was employed to estimate the microstructural parameters such as, crystallite size, lattice strain, lattice deformation stress and deformation energy density from the powder diffraction data obtained for the microwave synthesized hydroxyapatite (HA) and fluorapatite (FA) nanoparticles prepared under identical processing conditions of mixing and aging. The as-prepared powder particles were also characterized by transmission electron microscopy (TEM) method. The average crystallite size values estimated for HA and FA by XPPA were correlated to their respective transmission electron microscopy (TEM) analysis results. In addition, the estimated values of HA and FA were correlated to their in-vitro dissolution characteristics studied by ethylenediamine tetra-acetic acid (EDTA) titrimetric method. It is found that the average crystallite size estimated by W-H models is in good agreement with TEM results. The controlled in-vitro dissolution behavior of FA was found to be resulted out of its higher crystallite size, lower lattice strain and lower dislocation density compared to that of HA.

Index Terms—Hydroxyapatite, fluorapatite, biomedical applications, defects, X-ray peak profile analysis.

K. Venkateswarlu is with the Department of Physics and Department of Metallurgical and Materials Engineering, National Institute of Technology, Tiruchirappalli, 620015, Tamil Nadu, India (e-mail: kotharu.venkat@ gmail.com).
A. C. Bose is with the Department of Physics, National Institute of Technology, Tiruchirappalli, 620015, Tamil Nadu, India (e-mail: acbose@nitt.edu)
D. Sreekanth, M. Sandhya Rani, V. Muthupandi, and N. Rameshbabu are with the Department of Metallurgical and Materials Engineering, National Institute of Technology, Tiruchirappalli, 620015, Tamil Nadu, India (e-mail: sreekanth54@gmail.com, muthyala07@gmail.com, vmuthu@nitt.edu, rameshrohitht@gmail.com).

Cite: K. Venkateswarlu, D. Sreekanth, M. Sandhyarani, V. Muthupandi, A. C. Bose, and N. Rameshbabu, "X-Ray Peak Profile Analysis of Nanostructured Hydroxyapatite and Fluorapatite," International Journal of Bioscience, Biochemistry and Bioinformatics vol. 2, no. 6, pp. 389-393, 2012.