超音波噴霧熱分解法によるストロンチウムアパタイト粉体のキャラクタリゼーション

抄録

Strontiumapatite (Sr₁₀(PO₄)₆(OH)₂; SrAp) powder was prepared by the ultrasonic spray-pyrolysis technique and was characterized. Three kinds of starting solutions with a Sr/P molar ratio of 1.67 were prepared by mixing Sr(NO₃)₂, (NH₄)₂HPO₄ and HNO₃; the concentrations of Sr²⁺ and PO₄^3- were in the ranges of 0.10 to 0.50mol·dm^-3 and 0.06 to 0.30mol·dm^-3, respectively. These solutions were sprayed into the heating zone to prepare the SrAp powders. The heating zone was composed of two electric furnaces; the lower furnace served for the evaporation of the solvent from the droplets (400°C), the upper furnace for the pyrolysis of the precipitated metal salts (850°C). Easily sinterable SrAp powder was prepared by spray-pyrolysis from a starting solution containing 0.10mol·dm^-3 of Sr²⁺ and 0.06mol·dm^-3 of PO₄^3-. The resulting powder was composed of spherical and solid particles filled with fine primary particles. This SrAp powder was thermally stable up to 1200°C. Even without calcination and grinding operations, the relative densities of the compacts fired at 1200°C for 5h attained maxima of -96%. The microstructure of the sintered compacts appeared to be uniform; the average grain size was -2μm.