Heterogeneous Nucleation on a Conical Cavity

Heterogeneous nucleation in a conically shaped pit on the surface of a plane surface substrate is investigated. The growing process of a cluster on the substrate consists of three stages: growing within the conical cavity, at the cavity edge and outside the cavity. In every stage, the thermodynamic criterion of a cluster growing into a nucleus depends on both the conical cavity dimensions and the substrate materials. The free energy barrier for nucleus formation and the condition of twice nucleation are obtained.