Viscosity of Silica and Doped Silica Melts: Evidence for a Crossover Temperature

Autor: John C. Mauro, Charles R. Kurkjian, Prabhat K. Gupta, Walter Kob
Přispěvatelé: Laboratoire Charles Coulomb (L2C), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)
Rok vydání: 2021
Předmět:
Materials science
Crossover
supercooled liquids
Thermodynamics
FOS: Physical sciences
02 engineering and technology
Activation energy
01 natural sciences
Condensed Matter::Disordered Systems and Neural Networks
Viscosity
symbols.namesake
Impurity
0103 physical sciences
Materials Chemistry
[PHYS.COND.CM-DS-NN]Physics [physics]/Condensed Matter [cond-mat]/Disordered Systems and Neural Networks [cond-mat.dis-nn]
[PHYS.COND.CM-SM]Physics [physics]/Condensed Matter [cond-mat]/Statistical Mechanics [cond-mat.stat-mech]
ComputingMilieux_MISCELLANEOUS
glass
010302 applied physics
Arrhenius equation
Condensed Matter - Materials Science
Dopant
Doping
Materials Science (cond-mat.mtrl-sci)
Disordered Systems and Neural Networks (cond-mat.dis-nn)
Condensed Matter - Disordered Systems and Neural Networks
021001 nanoscience & nanotechnology
Condensed Matter::Soft Condensed Matter
silica
viscosity
Ceramics and Composites
symbols
0210 nano-technology
Glass transition
Zdroj: Journal of the American Ceramic Society
Journal of the American Ceramic Society, Wiley, 2021, pp.0. ⟨10.1111/jace.18090⟩
ISSN: 0002-7820
1551-2916
DOI: 10.48550/arxiv.2108.09487
Popis: Silica is known as the archetypal strong liquid, exhibiting an Arrhenius viscosity curve with a high glass transition temperature and constant activation energy. However, given the ideally isostatic nature of the silica network, the presence of even a small concentration of defects can lead to a significant decrease in both the glass transition temperature and activation energy for viscous flow. To understand the impact of trace level dopants on the viscosity of silica, we measure the viscosity-temperature curves for seven silica glass samples having different impurities, including four natural and three synthetic samples. Depending on the type of dopant, the glass transition temperature can vary by nearly 300 K. A common crossover is found for all viscosity curves around ~2200-2500 K, which we attribute to a change of the transport mechanism in the melt from being dominated by intrinsic defects at high temperature to dopant-induced defects at low temperatures.
Databáze: OpenAIRE
Externí odkaz: