The glaserite-like structure of double sodium and iron phosphate Na3Fe(PO4)2

The double sodium and iron phosphate Na3Fe(PO4)(2) was synthesized and studied by the XRD method, the second harmonic generation technique, and Mossbauer and IR spectroscopy. The compound crystallizes into a monoclinic system (space group C2/c) with unit cell parameters a = 9.0736(2) Angstrom, b = 5.0344(1) Angstrom, c = 13.8732(3) Angstrom, beta = 91.435(2)degrees and is found to be related to the K3Na(SO4)(2) structure type. The crystal structure was determined by Rietveld analysis (R-wp = 5.86, R-1 = 2.03). Iron cations occupy the M (Na) position while sodium cations occupy the X (K) and Y (K) positions of the glaserite-like structure. Mossbauer spectroscopy shows the presence of high-spin Fe3+ in octahedral coordination. (C) 2001 Academic Press.