Yuanyuan Cao Published Paper on Journal of Applied PhysicsViews [2831] Delivery time :2015-06-19 10:27:19

Dr. Yuanyuan Cao has published a paper titled as “A  nanoscale temperature-dependent heterogeneous nucleation  theory”  on 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 thermalfluctuations  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.