Viscosity and Fragility of Alkaline‐Earth Sodium Boroaluminosilicate Liquids

Abstract

Understanding the composition and temperature dependence of viscosity of silicate liquids is of the highest importance not only for geological processes but also for production of industrial glass. In this work, we have determined the temperature dependence of equilibrium liquid viscosity of 36 alkaline-earth sodium boroaluminosilicate liquids as a function of the Si/Al ratio and the type of alkaline-earth oxide (MgO, CaO, SrO, or BaO). We demonstrate that the isokom temperature at 10 12 Pa s (i.e., the glass transition temperature) generally increases with increasing Si/Al ratio, whereas the isokom temperatures at 10 4 and 10 1.5 Pa s exhibit a decrease with increasing [Al 2 O 3 ] in the peraluminous regime. The isokom temperatures decrease with increasing alkaline-earth size in the peralkaline regime, whereas they increase with increasing alkaline-earth size in the peraluminous regime. The liquid fragility index m exhibits a minimum value at an intermediate Si/Al ratio, with the position of the minimum increasing to a higher value of [Al 2 O 3 ] with increasing alkaline-earth size. We have discussed our findings in terms of the underlying structural and topological changes as a function of composition and temperature.

Extent of Disorder in Magnesium Aluminosilicate Glasses: Insights from 27Al and 17O NMR

“…Magnesium aluminosilicate glasses are among the prototypical amorphous oxides with fundamental implications for physical chemistry, geochemistry, and glass and materials sciences. Multicomponent Mg-bearing aluminosilicate glasses also have a wide range of applications in the glass and ceramics industry because the addition of Mg to aluminosilicate glasses enhances their chemical durability and mechanical properties (e.g., − ). They can also be potentially useful host materials for high-power laser generation .…”

Ionic Conductivity in Sodium–Alkaline Earth–Aluminosilicate Glasses

“…Potuzak and Smedskjaer reported the composition dependence of several physical properties (density, refractive index, thermal expansion coefficient, and elastic moduli) relevant to sodium–potassium interdiffusion and viscosity in a series of sodium–alkaline earth–boroaluminosilicate glasses. But their physical property studies do not help to clarify the specific role of aluminum in the composition dependence of ionic conduction because both boron and aluminum affect the glass network structure in boroaluminosilicate glasses.…”