Amorphous precursors of crystallization during spinodal decomposition

L. R. GÓMEZ; DANIEL A. VEGA

PHYSICAL REVIEW E

AMER PHYSICAL SOC

Lugar: New York; Año: 2011 vol. 83 p. 215011 - 215015

1539-3755

A general Landau’s free energy functional is used to study the dynamics of crystallization during liquid-solid spinodal decomposition (SD). The strong length scale selectivity imposed during the early stage of SD induces the appearance of small precursors for crystallization with icosahedral order. These precursors grow in densely packed clusters of tetrahedra through the addition of new particles. As the average size of the amorphousnuclei becomes large enough to reduce geometric frustration, crystalline particles with a body-centered cubic symmetry heterogeneously nucleate on the growing clusters. The volume fraction of the crystalline phase is strongly dependent on the depth of quench. At deep quenches, the SD mechanism produces amorphous structures arranged in dense polytetrahedral aggregates.