A molecular theory of crystal nucleation from the melt

We construct a molecular theory for the homogeneous nucleation of crystals from pure liquids by combining an order parameter theory of freezing with a square gradient approximation for the nonlocal dependence of free energy on density. We show the results of our theory for the free energy, radius, and shape of crystal nuclei as a function of supercooling, and compare with the conventional nucleation theory based on the capillarity approximation. We argue that the simple picture given by the conventional approach is qualitatively reasonable, although calculated values of the liquid–solid surface free energy may be inaccurate. We point out some of the limitations of our approach and stress the need for additional structural data on supercooled liquids.

[1]  T. Ramakrishnan Density-wave theory of first-order freezing in two dimensions , 1982 .

[2]  J. Faires Numerical Analysis , 1981 .

[3]  D. Oxtoby,et al.  A molecular theory for the solid–liquid interface , 1981 .

[4]  D. Uhlmann On the internal nucleation of melting , 1980 .

[5]  D. Frenkel,et al.  Computer Simulations of Freezing and Supercooled Liquids , 1980 .

[6]  Carl V. Thompson,et al.  On the approximation of the free energy change on crystallization , 1979 .

[7]  R. Cortès,et al.  X‐ray diffraction study of liquid mercury over temperature range 173 to 473 K , 1979 .

[8]  C. Hsu,et al.  Crystal nucleation and growth in liquid rubidium , 1979 .

[9]  J. Ross,et al.  A stochastic theory of cluster growth in homogeneous nucleation , 1975 .

[10]  J. H. Gibbs,et al.  Molecular theory of surface tension , 1975 .

[11]  D. P. Woodruff,et al.  The solid-liquid interface , 1974 .

[12]  A. J. Greenfield,et al.  X-Ray Determination of the Static Structure Factor of Liquid Na and K , 1971 .

[13]  John E. Hilliard,et al.  Free Energy of a Nonuniform System. III. Nucleation in a Two‐Component Incompressible Fluid , 1959 .

[14]  D. Turnbull Formation of Crystal Nuclei in Liquid Metals , 1950 .

[15]  N. S. Gingrich,et al.  The Effect of Temperature on the Atomic Distribution in Liquid Sodium , 1938 .

[16]  J. Lebowitz,et al.  Statistical Thermodynamics of Nonuniform Fluids , 1963 .

[17]  David Turnbull,et al.  Rate of Nucleation in Condensed Systems , 1949 .

[18]  R. Becker,et al.  Kinetische Behandlung der Keimbildung in übersättigten Dämpfen , 1935 .