Papers by Keyword: Non-Bridging Oxygen

Abstract: Glasses of the system {[ (TeO₂)₇₀ (B₂O₃)₃₀]₇₀ (ZnO)₃₀}_100-y (Er₂O₃)_y containing different concentration of Er2O3 (ranging from 0 to 5 mol %) was prepared from melt-quenching technique. The structural changes were studied by XRD analysis and FTIR analysis. The XRD pattern shows the glasses are amorphous. The higher concentration of Er₂O₃, the more unit of TeO₃ would transform to TeO₄ and formation of B-O vibrational groups. The density and molar volume was obtained attribute to non-bridging oxygen (NBO) and are found the density and molar volume of the glass system are increasing. The densities range from 3630 kg/m3 to 3960 kg/m3. The dielectric constant ε’ and dielectric loss factor ε’’ which were characterized in the frequency range 10^-2 – 10⁶ Hz over temperature range 50°C – 200 °C, show a larger value at lower frequency and higher temperature (above 110°C ). The results of dielectric response measurement show that interfacial polarization at low frequency, and orientation polarization at intermediate and high frequency.Keywords: Dielectric properties; Activation Energy; Rare Earth; Polarization; Non-Bridging Oxygen;

Abstract: The electrical resistivty (R) of BaO–CaO–SiO2–Al2O3 (BCSA) based glass, which was used in SOEC, was measured by impedance analyzer from room temperature to sealing temperature, and it was founded that electrical resistivity of all seal glass decreases with temperature. When temperature is lower than the soften temperature of glass, the electrical resistivity of all seal glass was no less than 107Ω∙cm. At 850°C, the resistivity of the 16BaO–16CaO–42SiO2–8Al2O3 glass (G1) reached 4.40×106Ω∙cm, and even at the sealing temperature, their resistivity was still above 105-106Ω∙cm. With the decrease of ratio of Si/B from 3 to 1, the electrical resistivity of glass decreased from 4.40×106Ω∙cm to 8.96×104Ω∙cm. The electrical resistivity of glass in BCSA system could be significantly affected by B2O3 and alkaline earth oxides. The results show that the electrical resistivity of glass was improved with the increasing of non-bridging oxygen and the average field strength. All glasses can be used as sealants at high temperature with no electrical shunting in SOEC.

Abstract: Glasses in the Bi2O3-B2O3-BaO-ZnO system were prepared using the normal melt quenching technology. The structure of the glasses was analyzed by using of the infrared spectra within the range 2000∼400cm-1. The relation among the properties such as density (D), thermal expansion coefficient (α) and transition temperature (Tg), Bi2O3 introducing content and structure of the glass have been discussed.