Investigation of the effects of nickel addition on the crystal structure and thermal properties of magnesium-based hydroxyapatite samples

In this study, the crystal structure and thermal properties of Magnesium (Mg)-based hydroxyapatite (HAp) samples, synthesized by a wet chemical method, doped with Nickel (Ni) at different amounts were investigated. The crystal structure refinement of the as-produced samples was carried out by X-ray diffraction (XRD) technique. The functional groups in the samples were determined by Fourier transform infrared (FTIR) spectroscopy. The thermal properties of the samples were investigated by using differntial thermal analysis (DTA) and thermogravimetric analysis (TGA) techniques. The morphologies and elemental compositions of the samples were examined by scanning electron microscopy equipped with energy dispersive X-ray (EDX) spectroscopy. With increasing Ni amount, these results were observed. The crystallite size, lattice parameters and crystallinity percent decrease. It was found that all the samples were thermally stable in the temperature range from 25 °C to 1000 °C. No any significiant change in the morphology was observed. It was determined that the Ca deficiency gradually increased with increasing amount of Ni.