Simulation of Ideal Crystal Superheating and Decay

Abstract

Molecular dynamics (MD) method is used to investigate time features of the transition of a superheated ideal crystal into liquid. Different levels of statistical description of the process are used. An approach to the calculation of the lifetime of a metastable crystal is developed. The homogeneous nucleation rate dependence on temperature is calculated. The decay under conditions of the constant rate heating is simulated as well. The limits of predictability of the MD method arising from chaotic properties of many-particle systems are shown for the problem concerned.

Keywords:

• Metastable states
• Homogeneous nucleation
• Molecular dynamics
• Chaotic properties
• Predictability

Acknowledgements

This research is partially supported by the program “Thermophysics and mechanics of the intensive energy impacts” of Russian Academy of Science, “Integratsiya” projects U0022 and I0661, by grant 03-07-90272v of Russian Foundation of Basic Research. V.V.S. is grateful for the support of the “Dynastia” foundation and the International center of fundamental physics in Moscow. The computations were performed on the cluster system granted by Deutscher Akademischer Austausch Dienst.

Notes

^†We use the term “decay” but not “melting” in order to emphasize the difference between the equilibrium melting at T = T_{m} (phase coexistence) and the spontaneous liquid nucleation inside the superheated solid at T > T_{m}.

^‡This expression was used in experimental investigations (e.g. see Refs. [23,24]) and MD calculations [13] of homogeneous nucleation rate).