ChemInform Abstract: New Bismuth Calcium Oxysilicate with Apatite Structure: Synthesis and Structural Characterization.

Abstract

New Bismuth Calcium Oxysilicate with Apatite Structure: Synthesis and Structural Characterization. -Ca4Bi4.3(SiO4)(HSiO4)5O0.95 is prepared by ultrasound-assisted dissolution of Ca(NO3)2·4H2O and Bi(NO3)3·5H2O in ethanolic HNO3 solution, addition of mesoporous silica KIT-6, heating to dryness (80°C, 12 h), and calcination (800°C, 12 h). The new oxysilicate has an apatite structure and crystallizes in the hexagonal space group P6 3 /m (powder XRD). The phase has an unusual quantity of cation vacancies in the crystal lattice. Lattice charge compensation is achieved through the partial replacement of O atoms of the SiO4 tetrahedra by OH groups. The presence of HSiO4 groups is confirmed by FT-IR, XPS, and thermal analysis. -(UVAROV*, V.; SHENAWI-KHALIL, S.; POPOV, I.; J. Solid State