Abstract. Qualitative XRD phase-analysis of four (x = 0.10, 0.20, 0.30, 0.40) selected compositions of the Sr (0.5+x) Sb (1−x) Fe (1+x) (PO 4 ) 3 (0 < x < 0.50) system was undertaken. XRD data shows the absence of a continuously solid solution. In fact, each composition is composed only of a mixture of the two end members, Sr 0.50 SbFe(PO 4 ) 3 (R3 space group) and SrSb 0.50 Fe 1.50 (PO 4 ) 3 (R3c space group), type-phases. Rietveld refinement method, using the XRPD technique, has been used for a quantitative phase-analysis of these compositions. In order to evaluate the relative errors of this experimental result, a set of standard phase-mixtures of both end compositions of the system was also quantified by the Rietveld method. Obtained results show the usefulness of this method for quantitative phase-analysis, particularly in geology including other classes of materials such clay and cement.

No abstract