Influence of the coordination defects on the dynamics and the potential energy landscape of two-dimensional silica
arXiv:2208.01011 · doi:10.1063/5.0118797
Abstract
The main cause of the fragile-to-strong crossover of 3D silica was previously attributed to the presence of a low energy cutoff in the potential energy landscape. The important question emerges about the microscopic origin of this crossover and the generalizibility to other glass-formers. In this work, the fragile-to-strong crossover of a model 2D glassy system is analyzed via molecular dynamics simulation, which represents 2D-silica. By separating the sampled defect and defect-free inherent structures, we are able to identify their respective density of state distributions with respect to energy. A low energy cutoff is found in both distributions. It is shown that the fragile-to-strong crossover can be quantitatively related to the parameters of the energy landscape, involving in particular the low-energy cutoff of the energy distribution. It is also shown that the low-energy cutoff of the defect-states is determined by the formation energy of a specific defect configuration, involving two silicon and no oxygen defect. The low-temperature behavior of 2D silica is quantitatively compared with that of 3D silica, showing surprisingly similar behavior.
arXiv comment11 pages, 7 figures
References in corpus (18)
- Relation Between the Widom line and the Strong-Fragile Dynamic Crossover in Systems with a Liquid-Liquid Phase Transition
- The relationship between fragility, configurational entropy and the potential energy landscape of glass forming liquids
- Fragile-to-strong transition and polyamorphism in the energy landscape of liquid silica
- Dynamics of simulated water under pressure
- Energy Barriers and Activated Dynamics in a Supercooled Lennard-Jones Liquid
- The potential energy landscape of a model glass former: thermodynamics, anharmonicities, and finite size effects
- Free energy and configurational entropy of liquid silica: fragile-to-strong crossover and polyamorphism
- What does the potential energy landscape tell us about the dynamics of supercooled liquids and glasses?
- Water-like anomalies as a function of tetrahedrality
- The Origin of the Fragile-to-Strong Crossover in Liquid Silica as Expressed by its Potential Energy Landscape
- Ring statistics in 2D-silica: effective temperatures in equilibrium
- Dynamics of liquid silica as explained by properties of the potential energy landscape
- Understanding the fragile-to-strong transition in silica from microscopic dynamics
- Characterization of the non-Arrhenius behavior of supercooled liquids by modeling non-additive stochastic systems
- Non-Arrhenius behavior and fragile-to-strong transition of glass-forming liquids
- Structural Signatures for Thermodynamic Stability in Vitreous Silica: Insight from Machine Learning and Molecular Dynamics Simulations
- Properties of ideal Gaussian glass-forming systems
- Relating local structures, energies, and occurrence probabilities in a two-dimensional silica network