Synthesis And Sintering Studies Of Nanocrystalline Hydroxyapatite Powders Doped With Magnesium And Zinc

In this research, we have synthesized nanocrystalline hydroxyapatite (Ca 10(PO 4) 6(OH) 2, HAp) powders doped with magnesium and zinc using the water-based sol-gel technique and characterized them. Calcium nitrate and triethyl phosphite were used as starting materials. These chemicals were dissolved in distilled water, separately, under vigorous stirring. As-prepared calcium nitrate sol was added drop wise into the hydrolyzed phosphite sol and then aged and dried. Dried gel was then crushed into fine white powders with the help of mortar and pestle and a measured amount of magnesium oxide and zinc oxide powders were added to the crushed amorphous powders, separately. Calcination was carried out at 250-500°C. Morphology of the powders was determined using transmission electron microscopy. TEM results revealed that the particle size diameter of powders were in the range of 5-10 nm. Phase analyses were carried out using powder X-ray diffraction technique. As-synthesized powders were also pressed uniaxially in a steel mold to prepare dense ceramic structures. These green structures were sintered at 1300°C for 6 h in a muffle furnace for densification. Highest sintered density of 3.29 g/cc was measured for magnesium-doped powder