Investigations of tin (II/IV) phosphates prepared by various methods, Mössbauer study and X-ray diffraction characterization

Using various methods different tin phosphate samples were prepared. One of them was amorphous, while the others were crystalline with monoclinic structure, having unit cell parameters as follows: a=4.586 Å, b=13.618 Å, c=5.818 Å, β=99.61° [Sn (H2PO4)2] and a=8.612 Å, b=4.964 Å, c=15.860 Å, β=98.87° [Sn(HPO4)2], respectively. The crystal water content and the method of thermal decomposition of the samples were determined. The chemical composition of the end products of preparations was determined by promt-gamma activation analysis and was found to be Sn:P=1:2 for all samples independent of their preparation method. The oxidation state of tin atoms in samples as determined by Mossbauer spectroscopy was mainly +2 in sample no. 2, while in some other samples it was +4.