CHARACTERIZATION OF VARIOUS APATITES POWDERS PREPARED BY ULTRASONIC SPRAY-PYROLYSIS TECHNIQUE

Abstract

Various apatites powders with the formula of M10(PO4)6(OH)2 (M=Mg, Ca, Sr, Ca+Sr and Ba) were prepared by ultrasonic spray-pyrolysis technique. In the cases of M=Ca, Sr, Ca+Sr and Ba, the hydroxyapatite, strontium apatite, strontium-substituted hydroxyapatite and barium apatite were respectively formed. In the case of M=Mg, however, no crystalline compound was present in the resulting powder; Mg3(PO4)2 formed at ~700°C. The relative densities of the hydroxyapatite, strontium apatite and strontium-substituted hydroxyapatite compacts fired at 1200°C for 5h attained ~93%, 96% and 95%, respectively.