Williamson-Hall based X-ray peak profile evaluation and nano-structural characterization of rod-shaped hydroxyapatite powder for potential dental restorative procedures

Abstract

<abstract> In the present paper, nanometer scale hydroxyapatite powders with a rod-like shape, were prepared using a combined ultrasonic and microwave heating-based method. Subsequent annealing of as-synthesized powders at 800 ℃ for 2 h produced nanoparticles with a rectangular and granular morphology. The hydroxyapatite particles were characterized using X-ray diffraction and Fourier transform infrared spectroscopy methods. Also, nanoparticle size and morphology were investigated using transmission electron microscopy and field emission scanning electron microscopy. A comparable selected area electron diffraction (SAED) analysis also showed results in line with X-ray powder diffraction patterns. The resulting X-ray diffraction peaks indicated that the powders were highly crystalline in nature and no impure phases were present. The X-ray diffraction data, was also used to study the effects of peak broadening by using the Williamson–Hall (W–H) analysis technique. The analysis used the uniform deformation model (UDM), uniform stress deformation model (USDM) and uniform deformation energy density model (UDEDM) to determine physical parameters like crystallite size, lattice strain, stress and energy density. The results of the W-H analysis were found to be comparable to the results obtained from microscopy studies. Importantly, the studies confirmed the synthesized nano- hydroxyapatite powders had morphologies similar to those found in dental hard tissues. </abstract>