Synthesis and characterization of gallo-silicate carbonate cancrinite

Gallosilicate cancrinite with carbonate anion, Na8[GaSiO4]6(CO3)1.72(H2O)5 has been synthesized at low temperature by hydrothermal method (373 K). The white crystalline cancrinite powder was characterized by IR, X-ray powder diffraction, TGA, SEM, and MAS NMR. Crystal structure was refined in the space group P63, from X-ray powder diffraction data using Rietveld refinement method with a = 12.5899 Å, c = 5.1424 Å. The average Al-O bond distance is 1.8109 Å and Si-O bond distance is 1.5847 Å, while the T-O-T angle is found to be 138.793°. TGA shows thermal behavior of the carbonate anion inside the cancrinite cages. The single resonance line in the 29Si spectrum confirms strictly alternating order of Ga and Si in the framework. The SEM picture shows hexagonal needle shaped structures.