Crystal chemistry of immobilization of divalent Sr in ceramic matrix of sodium zirconium phosphates

Sodium zirconium phosphate (NZP) is a potential material for immobilization of nuclear effluents. It was observed up to ∼1.98 mol% (6.07 wt%), of strontium could be loaded into NZP formulations without significant changes of the three-dimensional framework structure. The crystal chemistry of Na1−xSrx/2Zr2P3O12 (x = 0.1–1.0) phases has been investigated using General Structure Analysis System programming. The SrNZP phases crystallize in the space group R-3c and Z = 6. Powder diffraction data have been subjected to Rietveld refinement to arrive at a satisfactory structural convergence of R-factors. The PO4 stretching and bending vibrations in the Infra red (IR) region have been assigned. SEM and EDAX analysis provide evidence of Sr in the matrix.