The structure of 70(2Bi2O3-V2O5) - 30SrBO7 measured with X-ray diffraction and SEM methods

The structure changes of 70(2Bi2O3-V2O5)-30SrB4O7 glass occurred during increase in temperature was measured by XRD and SEM. The polycrystalline strontium–borate, SrB4O7 was synthesized via a solid state reaction route that involved heating stoichiometric mixtures of analytical grade SrCO3 and H3BO3 at 1073 K for 12 hours. Next, sample of a composition of 70(2Bi2O3-V2O5)-30SrB4O7 (in %mol) were prepared from reagent-grade Bi2O3, V2O5 and preprepared SrB4O7. Samples of glass were prepared by the conventional melt quenching technique. The melting was conducted in alumina crucibles at 1373 K for 2 hours. The melt was poured onto a preheated (573 K) brass plate and pressed by another plate to obtain flat circular disks of 1–2 mm thickness and 20–30 mm in diameter. In the following, sample symbols were simplified to xBiV(100x)SBO. Samples were heat-treated at 813K for 1 h. The presence of crystalline phases and their phase composition were studied using an X-ray diffraction (XRD) method using a Philips X'Pert Pro MPD system with CuKα radiation. The XRD measurements were conducted at room temperature. 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).