The topography of strontium–borate glasses and glass-ceramics containing nanocrystallites of Bi2VO5.5. measured with SEM method

The topography of strontium–borate glasses and glass-ceramics containing nanocrystallites of Bi2VO5.5. was measured by SEM. In order to prepare glass-ceramics composites two compounds: Bi2VO5.5 and SrB4O7 were synthesized via a solid state reaction route. The Bi2VO5.5 was synthesized from the stoichiometric mixture of initial powders of Bi2O3 and V2O5 which were ball-milled in pure acetone for 6 h at room temperature. The milling was performed in steps of 1 h with rest intervals of 10min. The mixture was heated up to 1020K in air and kept at this temperature for 24 h. The heating and cooling rate was of 50K h-1. The obtained powder was checked by X-ray diffraction method. The SrB4O7 was synthesized from the stoichiometric mixture of analytical grade SrCO3 and H3BO3 which were mashed in a mortar. Next the mixture was heated up to 1073K and kept at this temperature for 12 h.Samples of a composition of xBi2VO5.5–(100x)SrB4O7, where =30, 35, 40, 45, and 50 (in mol%) were prepared by the conventional melt quenching technique. The melting was conducted in alumina crucibles at 1373K for 2 h. The melts were poured onto a preheated (573 K) brass plate and pressed by another plate to obtain flat circular disks of 1–2mm thickness and 20–30mm diameter. In the following, sample symbols were simplified to xBiV(100x)SBO. All materials were crystallized in order to obtain glass-ceramics nanocomposites. Samples were heat-treated at 813K for 3 h. The topography of the samples was investigated using a Scanning Electron Microscope (SEM), FEI Company Quanta FEG250 with Energy Dispersive X-ray Analysis (EDAX Genesis APEX 2i with ApolloXSDD Spectrometer). SEM measurements were conducted on fractured samples on which a 7 nm thick gold layer was deposited, using a 10 or 20 kV beam accelerating voltage with a SE-ETD (secondary electron Everhart–Thornley detector) detector working in the high vacuum mode (pressure 104 Pa).