我所曹媛媛讲师在国际期刊Journal of Applied Physics发表论文阅读次数 [1205] 发布时间 :2015-06-19 10:27:19
我所曹媛媛讲师论文:A nanoscale temperature-dependent heterogeneous nucleation theory,发表于国际期刊Journal of Applied Physics。A nanoscale
temperature-dependent heterogeneous nucleation theory
Journal of Applied Physics 117(2015),
224303 (PDF-File)
Y. Y. Cao and G. W. Yang*
Classical nucleation theory
relies on the hypothetical equilibrium of the whole nucleation system, and
neglects the thermal fluctuations of the surface; this is because the high
entropic gains of the (thermodynamically extensive) surface would lead to multiple
stable states. In fact, at the nanometer scale, the entropic gains of the
surface are high enough to destroy the stability of the thermal equilibrium
during nucleation, comparing with the whole system. We developed a temperature-dependent
nucleation theory to elucidate the heterogeneous nucleation process, by considering
the thermal fluctuations based on classical nucleation theory. It was found
that the temperature not only affected the phase transformation, but also
influenced the surface energy of the nuclei. With changes in the Gibbs free
energy barrier, nucleation behaviors, such as the nucleation rate and the
critical radius of the nuclei, showed temperature-dependent characteristics
that were different from those predicted by classical nucleation theory. The
temperature-dependent surface energy density of a nucleus was deduced based on
our theoretical model. The agreement between the theoretical and experimental
results suggested that the developed nucleation theory has the potential to
contribute to the understanding and design of heterogeneous nucleation at the
nanoscale.