The structural response of network former mixing in barium borosilicate glasses: Part 1

M Brehl and BJA Moulton and W Xie and MR Cicconi and NS Tagiara and D Möncke and A Hajian and U Deisinger and A Roosen and U Schmid and EI Kamitsos and J Du and D de Ligny, JOURNAL OF THE AMERICAN CERAMIC SOCIETY, 109, e70459 (2025).

DOI: 10.1111/jace.70459

A glass series with constant similar to 30 mol% BaO in the BaO-B2O3-SiO2 system was studied as a function of SiO2/B2O3 ratio. This system has been studied in-depth to reveal the structure, Part 1, and its relationship to the mechanical properties, Part 2. Both the B coordination and network polymerization are quantified both experimentally, using Raman, IR, and 11B NMR spectroscopies, and theoretically, using classical molecular dynamics (MD) simulations with effective partial charge potentials with composition dependent boron parameters. These results show that IIIB, threefold-coordinated boron, increases linearly with increasing boron, at the expense of IVB. The Q 3 equilibrium constant decreases slightly with boron addition up to 37 mol%, whereas at greater B2O3 contents, the silica tetrahedra become more polymerized. These trends are reinforced by MD simulation results, which show that the average connectivity, polymerization, and ring size are directly related. The glass transition temperature increases with increasing silica content, where the range of temperatures follows the packing density. The BaO-B2O3-SiO2 system shows systematic trends from high to low oxygen packing between the binary borate glasses to the binary silicate glasses, indicating a high degree of predictability for properties controlled by density.

Return to Publications page