VLS（気相-液相-固相）成長したCdおよびZn微結晶の均質核生成

抄録

Cd or Zn fine crystals having the shape of whisker or polyhedrons were grown by a physical vapor deposition method. Their growth mechanism was VLS (Vapor-Liquid-Solid) growth. The nucleation of the crystal growth occurred in the eutectic alloy droplet (homogeneous nucleation) and did not occur at the interface between the droplet and a glass substrate (heterogeneous nucleation). The purpose of the present study was to explain this reason.
In order to decide the nucleation type (homogeneous or heterogeneous), we introduced the parameter Y defined as Y=γ_SG−(γ_LG+γ_SL), where γ_SG, γ_LG and γ_SL are the interfacial tensions between the crystal and the glass, between the liquid and the glass, and between the crystal and the liquid, respectively. When Y>0, the nucleation was homogeneous. When Y<0, it became heterogeneous.
In the case of VLS-grown Cd or Zn crystals, it was found from the data on the surface tension that the parameter Y was positive. Therefore, it was concluded that the nucleation of the Cd or Zn crystals was homogeneous.