Epitaxial homogeneous nucleation

Manecki et al. (2000b) used the same three apatites to study both homogeneous and epitaxial heterogeneous nucleation. For this, AFM, SEM, optical microscopy, EDS, Fourier-transformed infrared (FTIR) spectroscopy, and XRD were used to characterize the apatites and the reaction... 

If a c = a sA then = 0 and the new phase C wets the interface. If nucleation barrier for the new phase C will vanish. On the other hand, if homogeneous nucleation. This would be the case if the original interface were nearly coherent, i.e., A/B is an epitaxial structure. Heterogeneous nucleation would be effectively suppressed in this case. In general, the nucleation barrier for C, AG UC depends on

0. These general features are applicable irrespective of whether C is a metastable... 

The saccharin nucleation data were not consistent with eqn (2) for any value of when using the expression for C derived for homogeneous nucleation. However, assuming that nucleation occurs epitaxially at the saccharin/polymer interface, the correct expression for C should be approximately ... 

The circumstances of formation of a dislocation loop at the surface of a strained film considered in the preceding section presumed no conditions to make dislocation nucleation more likely at one location then at another. This is the essential characteristic of homogeneous nucleation. In reality, epitaxial films are never geometrically perfect. Irregularities can take the form of surface or interface features (Jesson et al. 1993), precipitate particles due to... 

Furthermore, kinetic results from both small-angle X-ray scattering and DSC indicate that the crystallization mechanism is altered due to the silicate from that of homogeneous nucleation for the pure polymer to heterogeneous and epitaxial nucleation with the increase of the inorganic material. 

Keywords nudeation, primary nudeation, nudeation rate, heterogeneous nudeation, supercooling, homogeneous nudeation, aimeal-ing, self-nudeation, nucleating agents, epitaxy, nudeation in blends, nudeation in copolymers, spherulite, lamellae, p-crystal form, secondary nudeation, nudeation rate. 

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