Topology and glass structure evolution in (BaO)x((B2O3)32(SiO2)68)100 − x ternary—Evidence of rigid, intermediate, and flexible phases

Abstract

We examine variations in the glass transition temperature (T(g)(x)), molar volume (V(m)(x)), and Raman scattering of titled glasses as a function of modifier (BaO) content in the 25% < x < 48% range. Three distinct regimes of behavior are observed; at low x, 24% < x < 29% range, the modifier largely polymerizes the backbone, T(g)(x) increase, features that we identify with the stressed-rigid elastic phase. At high x, 32% < x < 48% range, the modifier depolymerizes the network by creating non-bridging oxygen (NBO) atoms; in this regime T(g)(x) decreases, and networks are viewed to be in the flexible elastic phase. In the narrow intermediate x regime, 29% < x < 32% range, T(g)(x) shows a broad global maximum almost independent of x, and Raman mode scattering strengths and mode frequencies become relatively x-independent, V(m)(x) show a global minimum, features that we associate with the isostatically rigid elastic phase, also called the intermediate phase. In this phase, medium range structures adapt as revealed by the count of Lagrangian bonding constraints and Raman mode scattering strengths.

Structural Roles of Boron and Silicon in the CaO-SiO2-B2O3 Glasses Using FTIR, Raman, and NMR Spectroscopy

“…Borosilicate-based glasses and melts are important materials because of their wide applications in glass industry. [1][2][3][4] and metallurgical industry. [5][6][7][8][9] The macroscopic properties of these glasses and melts are primarily determined by the microscopic structure; thus it is of crucial importance to acquire the structural environments of boron (B) and silicon (Si) including the role and coordination conditions.…”

“…Based on the areas of the obtained peaks (A i ) and the Raman scattering coefficient (S i ), the mole fractions (X i ) (i = 0, 1, 2, 3) could be calculated by Eq. [1]: [19,30,31] …”

“…Second, recently several studies [5,7,17] investigated the viscosities of boron-bearing melts from the prospect of qualitative analysis of the melt structures using Fourier transformation infrared (FTIR) and Raman spectra. Third, because of the crucial importance of borosilicate glasses, many studies have explored the structures of borosilicate glasses [1][2][3][4] and substantial knowledge has been obtained.As for the Si-related structures, there were five structural units of SiO 4 tetrahedral, [18][19][20][21] which could be denoted as Q i (Si) (i = 0, 1, 2, 3, 4), where i represents the number of bridging oxygens (BO). The mole fraction of these structural units could be derived based on the deconvolutions of the Raman or magic angular spinning nuclear magnetic resonance (MAS-NMR) curves.…”

“…Second, recently several studies [5,7,17] investigated the viscosities of boron-bearing melts from the prospect of qualitative analysis of the melt structures using Fourier transformation infrared (FTIR) and Raman spectra. Third, because of the crucial importance of borosilicate glasses, many studies have explored the structures of borosilicate glasses [1][2][3][4] and substantial knowledge has been obtained.…”

Tunable stoichiometry of SiO x - BaTiO y - BO z fabricated by multitarget pulsed laser deposition

“…1,2 Materials having different stoichiometries from AF45 would provide different properties, but the challenge is being able to quickly and efficiently generate thin films that can be evaluated for capacitance measurements, breakdown measurements, as well as potential heat treatments that may be required to obtain the desired properties. Schott alkali-free commercial (AF45) grade glass includes BaO, B 2 O 3 , and SiO 2 , and is a very successful commercial product.…”