Hydrothermal synthesis of compounds in the fresnoite mineral family (Ba2TiSi2O8)

Crystals of Ba2TiSi2O8, Sr2TiSi2O8, and Ba2VSi2O8, all belonging to the fresnoite family were prepared by the hydrothermal method. Attempts to synthesize other members by substitution at the alkaline earth site, transition metal site, and tetrahedral site were not successful, but did lead to the formation of a variety of other mineral phases as well as the incommensurate structure, Ba2TiGe2O8. Structural studies on this compound and analysis of the other known fresnoite phases were performed to elucidate the nature of the incommensurate structure.

Materials crystallizing from the hydrothermal TiO2+SiO2+Ba(OH)2 system.Figure optionsDownload as PowerPoint slideResearch highlights
► A variety of products crystallized from the Ba(OH)2–TiO2–SiO2 hydrothermal system.
► Isolation of several fresnoite derivatives.
► Structural study on the incommensurate Ba2TiGe2O8 material.