Journalartikel

Jahr der Veröffentlichung: 2000

Seiten: 871-877

Zeitschrift: Journal of Inorganic and General Chemistry

Bandnummer: 626

Heftnummer: 4

ISSN: 0044-2313

Verlag: Wiley

Abstract: 
Mn3SiO4F2 was synthesized by chemical vapour transport in a temperature gradient (800-->700 degrees C) using MnF2 as precursor and iodine as transport agent. SiO2 was provided from the wall of the used silica tubes. The chemical composition of the crystals was determined by EELS and EDX analysis. The structure of Mn3SiO4F2 was determined and refined to R(\F\) = 0.039, wR(F-2) = 0.087, respectively. The orthorhombic phase crystallizes in the space group Pnma (No. 62) with a = 10.758(2) Angstrom, b = 9.145(1) Angstrom, c = 4.850(1) Angstrom and Z = 4. Two crystallographically different Mn-atoms are surrounded by oxygene and fluorine octahedrally. Si is tetrahedrally surrounded only by oxygen. IR-measurements proved that in Mn3SiO4F2 no substitution of F- by OH- takes place as in the mineral norbergite (Mg3SiO4(OH,F)(2)).