Effect of B2O3 on Structure and Properties of CaO-MgO-B2O3-Al2O3-SiO2 Glasses

xB(2)O(3)-(1 - x) (60SiO(2)-15Al(2)O(3)-15MgO-10CaO) glasses with various x around 5-30 mol% at the step of 5 mol% are prepared by the melting-quenching method at 1,450 A degrees C for 3 h. The IR data indicate that replacing other components by B2O3 levels up the amount of [BO4] tetrahedron and boron-oxygen rings, forcing [AlO4] tetrahedron to drop gradually. The glass transition temperature (T-g), crystallization temperature (T-c) and thermal stability (a dagger T) rise when B2O3 is present in lower concentrations (a parts per thousand currency sign20 mol%); accordingly the glass network enhances. However, further increase in concentration of B2O3 (> 20 mol%) reduces the T-g, T-c and a dagger T. We utilize temperature-gradient furnace to measure the G6 glass, while the re-melt sample and crystallized phase are observed from polarizing microscope destroying microstructure. As B2O3 content move up, falls in dielectric constant (epsilon(r)) and loss (tan delta) can be associated with drop of cations polarizability as well as concentration, along with glass network rigidity ascending.