LAYERED MIXED TIN-TITANIUM PHOSPHATES

Mixed crystalline tin-titanium phosphates with variable tin-to-titaniu m molar ratio have been prepared by precipitation of soluble salts of the metal (IV) with phosphoric acid and refluxing the amorphous solids in 17 M H3PO4. The new materials are characterized by chemical textur al and thermal analysis and x-ray powder diffraction. The tin-titanium phosphates are solid solutions showing an isomorphic substitution of tin by titanium in the alpha-tin phosphate lattice and tin substitutio n in the gamma-titanium phosphate lattice. In both cases, the solubili ty is partial. The coexistence of both saturated phases is observed in samples of composition between the solubility limits.