Cooling rate effects in sodium silicate glasses: Bridging the gap between molecular dynamics simulations and...

Area of Science:

• Materials Science
• Computational Chemistry
• Glass Science

Background:

• Molecular dynamics (MD) simulations are vital for predicting glass structure and properties.
• MD simulations are limited to short time scales, requiring fast cooling rates.
• Comparing MD results to experimental data for laboratory-cooled glasses is challenging due to timescale differences.

Purpose of the Study:

• To investigate the effect of cooling rates on glass structure using MD simulations.
• To understand the relationship between thermal history and structural ordering in glasses.
• To develop methods for comparing MD simulation results with experimental data.

Main Methods:

• Performed MD simulations of sodium silicate glass across a wide range of cooling rates (0.01–100 K/ps).
• Analyzed the impact of varying cooling rates on short-range and medium-range order.
• Examined the decoupling of enthalpy and volume relaxation functions.

Main Results:

• Thermal history significantly influences medium-range order but minimally affects short-range order in sodium silicate glass.
• Enthalpy relaxation plateaus rapidly with decreasing cooling rate, while density relaxation is slower.
• A decoupling effect was observed between enthalpy and volume relaxation.

Conclusions:

• MD simulations can capture the influence of thermal history on glass structure.
• Extrapolation techniques enable meaningful comparison between MD simulations and experimental data for glasses cooled at slower rates.
• Findings bridge the gap between computational predictions and experimental observations in glass science.