Arrhenian to non-Arrhenian crossover in glass melt viscosity

Journal Article · 07 August 2023 · Journal of Non-Crystalline Solids

DOI: https://doi.org/10.1016/j.jnoncrysol.2023.122556 · OSTI ID:2053115

Hrma, Pavel ^[1]; Ferkl, Pavel  ^[2]; Kruger, Albert A. ^[3]

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1. AttainX, Support Services Contractor to the USDOE Office of River Protection (ORP), Richland, WA (United States)
2. Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
3. USDOE Office of River Protection (ORP), Richland, WA (United States)

The activation energy for glass melt viscosity is a function of temperature, i.e., non-Arrhenian, within a middle range of viscosity values (typically, between 10² and 10¹⁰ Pa s) and constant, i.e., Arrhenian, outside this range. At the low-viscosity end, the Arrhenian to non-Arrhenian transition (termed the crossover) falls within the glass processing range: glass melting and fining occur within the Arrhenian range while glass forming occurs within the non-Arrhenian range. By the Adam-Gibbs equation, the configuration entropy is nearly constant at high temperatures (low viscosities), where the glass melt turns into a simple liquid, and decreases with decreasing temperature (increasing viscosity) as the glass is increasingly polymerized. In the present study, the power-law function and hyperbolic tangent function are used to express the configuration entropy as a function of temperature. The viscosity crossover is defined as the point at which onset of structural grouping is causing the configuration entropy to deviate from its high-temperature value. In conclusion, it appears that the limited range of the configuration entropy of the fully depolymerized melt imposes a restriction on the crossover viscosity; for well-defined glass families, such as float glasses or nuclear waste glasses, the crossover point can be defined using a fixed, i.e., composition-independent, viscosity value.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
• Sponsoring Organization: USDOE
• Grant/Contract Number: AC05-76RL01830
• OSTI ID: 2053115
• Report Number(s): PNNL-SA--185520
• Journal Information: Journal of Non-Crystalline Solids, Journal Name: Journal of Non-Crystalline Solids Vol. 619; ISSN 0022-3093
• Publisher: ElsevierCopyright Statement
• Country of Publication: United States
• Language: English