Stoichiometry of Luminescent Apatites

Abstract

Total chemical analysis of luminescent apatite together with quantitative x-ray diffraction analysis for secondary phases have made it possible to delineate the maximum permissible nonstoichiometry. Based on the accuracy of the various methods and expressed as a deficiency of calcium, the extent of nonstoichiometry is less than the absence of one calcium in every 380 calcium sites. Quantitative xperimental evidence is also presented to support the hypothesis for charge compensation of antimony by a corresponding oxygen substitution at halogen sites. Stoichiometry of Luminescent Apatites In a previous publication (1), the authors reported studies on the phase relationships of calcium halo-phosphate phosphor systems. Of major interest were pertinent compatibil ity triangles and tetrahedra. The question of the extent of nonstoichiometry of lumi-