Maximum superheating and undercooling: Systematics, molecular dynamics simulations, and dynamic experiments Academic Article uri icon

abstract

  • The maximum superheating and undercooling achievable at various heating (or cooling) rates were investigated based on classical nucleation theory and undercooling experiments, molecular dynamics (MD) simulations, and dynamic experiments. The highest (or lowest) temperature Tc achievable in a superheated solid (or an undercooled liquid) depends on a dimensionless nucleation barrier parameter and the heating (or cooling) rate Q. depends on the material: [formula presented] where sl is the solid-liquid interfacial energy, Hm the heat of fusion, Tm the melting temperature, and k Boltzmanns constant. The systematics of maximum superheating and undercooling were established phenomenologically as =(A0b log10Q)c(1c)2 where c=Tc/Tm, A0=59.4, b=2.33, and Q is normalized by 1 K/s. For a number of elements and compounds, varies in the range 0.28.2, corresponding to maximum superheating c of 1.061.35 and 1.081.43 at Q1 and 1012 K/s, respectively. Such systematics predict that a liquid with certain cannot crystallize at cooling rates higher than a critical value and that the smallest c achievable is 1/3. MD simulations (Q1012 K/s) at ambient and high pressures were conducted on close-packed bulk metals with Sutton-Chen many-body potentials. The maximum superheating and undercooling resolved from single-and two-phase simulations are consistent with the cQ systematics for the maximum superheating and undercooling. The systematics are also in accord with previous MD melting simulations on other materials (e.g., silica, Ta and -Fe) described by different force fields such as Morse-stretch charge equilibrium and embedded-atom-method potentials. Thus, the cQ systematics are supported by simulations at the level of interatomic interactions. The heating rate is crucial to achieving significant superheating experimentally. We demonstrate that the amount of superheating achieved in dynamic experiments (Q1012 K/s), such as planar shock-wave loading and intense laser irradiation, agrees with the superheating systematics. 2003 The American Physical Society.

published proceedings

  • Physical Review B

author list (cited authors)

  • Luo, S., Ahrens, T. J., an, T., Strachan, A., Goddard, W. A., & Swift, D. C.

citation count

  • 223

complete list of authors

  • Luo, Sheng-Nian||Ahrens, Thomas J||Çağın, Tahir||Strachan, Alejandro||Goddard, William A||Swift, Damian C

publication date

  • October 2003