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 similar 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. (C) 2012 Elsevier B.V. All rights reserved.