HAnanorods with an aspect ratio value between 6 and 7 were obtained. XRD analysis showed that the final product of calcined HA was pure. Rietveld analysis also revealed high purity and the dimensions of the unit cell of calcined HA, indicating a hexagonal structure. The nanorod formation has been attributed to “oriented attachment” mechanism, where HA crystallites stick together on high energy plane and template the growth in one particular direction. FTIR showed presence of minor CO3 2−
dissolution at high temperatures of 700 ◦C