Energy landscape picture of supercooled liquids: Application of a generalized random energy model
arXiv:cond-mat/0303520 · doi:10.1063/1.1574781
Abstract
The thermodynamic and kinetic anomalies of supercooled liquids are analyzed from the perspective of energy landscapes. A mean field model, a generalized random energy model of liquids is developed, which exhibits a dynamical transition of the onset of slow dynamics at T_0, alteration of the nature of motion from the saddle-to-saddle to minimum-to-minimum motion at T_c, and an ideal glass transition at T_k. If the energy spectrum of the configurations has a low energy tail, the model also allows a thermodynamic liquid-liquid transition at T_l. The liquid-liquid transition of the model is correlated to the kinetic fragile-strong transition accompanied by the anomalous slowing down of motion. Fragility of the system is classified in terms of features of the energy landscape such as ruggedness of the potential energy surface, size of the cooperative motion invoked in a transition from one configuration to another, and energy needed to deform the local structure in the cooperative motion. A simple relation is found between diffusion constant, D and the saddle index of the potential energy surface, f, as , where a depends on the size of the cooperative motion.
arXiv commentto appear in J. Chem. Phys
References in corpus (20)
- Dynamical heterogeneities in a supercooled Lennard-Jones liquid
- String-like Clusters and Cooperative Motion in a Model Glass-Forming Liquid
- The relationship between fragility, configurational entropy and the potential energy landscape of glass forming liquids
- Fragilities of Liquids Predicted from the Random First Order Transition Theory of Glasses
- Fragile-to-strong transition and polyamorphism in the energy landscape of liquid silica
- Thermodynamics of glasses: a first principle computation
- Configurational Entropy and Diffusivity of Supercooled Water
- Microscopic Theory of Heterogeneity and Non-Exponential Relaxations in Supercooled Liquids
- Dynamics of simulated water under pressure
- Computer simulations of liquid silica: equation of state and liquid-liquid phase transition
- Saddle Points and Dynamics of Lennard-Jones Clusters, Solids and Supercooled Liquids
- Energy landscape of a Lennard-Jones liquid: Statistics of stationary points
- The thermodynamical liquid-glass transition in a Lennard-Jones binary mixture
- Metastable states as a key to the dynamics of supercooled liquids
- Instantaneous Normal Mode Analysis of Supercooled Water
- Nanometer Scale Dielectric Fluctuations at the Glass Transition
- Fragile vs strong liquids: a saddles ruled scenario
- Apparent finite-size effects in the dynamics of supercooled liquids
- Configuration space connectivity across the fragile to strong transition in silica
- Entropy, Dynamics and Instantaneous Normal Modes in a Random Energy Model
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- Free energy and configurational entropy of liquid silica: fragile-to-strong crossover and polyamorphism
- Physics of the liquid-liquid critical point
- Non-Gaussian energy landscape of a simple model for strong network-forming liquids: accurate evaluation of the configurational entropy
- Size dependence of dynamic fluctuations in liquid and supercooled water