Nucleation of Crystals in Solution
نویسنده
چکیده
Figure 1. Schematic illustration of the two-step mechanism of nucleation of crystals. A dense liquid cluster forms. A crystal nucleus may form inside the cluster. Top: Macroscopic viewpoint of events. Bottom: The free-energy ΔG along two possible versions of the two step nucleation mechanism. 0 L L G − Δ is the standard free energy of formation of dense liquid phase and 0 C G Δ —that of formation of clusters. If the dense liquid is unstable and 0 L L G − Δ > 0, the dense liquid exists as mesoscopic cluster, 0 L L G − Δ transforms to 0 C G Δ , and upper curve applies; if dense liquid is stable, 0 L L G − Δ < ; this case is depicted by lower curve. * 1 G Δ is the barrier for formation of a cluster of dense liquid, * 2 G Δ – for a formation of a crystalline nucleus inside the dense liquid.
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