The velocity source concept

摘要

Traditional kinematics wave theory neglects considerations involving free energy of a surface and nucleation at the boundary of a surface. As a consequence, strictly speaking this theory is only applicable to freely floating perfect crystals, and when applied to more complex situations the conclusions may be false. In this paper we argue that boundary conditions, to be taken into account at interface junctions, affect the shape of the crystal. The effect is either microscopic kor macroscopic. In the firs case, we have a "kinetic meniscus", a curved transition of the size of the critical radius. In the second case, the growth rate is affected macroscopically and we may consider the boundary as a "velocity source" for the affected interface. These concepts are essential elements in a version of kinematics wave theory that is applicable to all physically relevant situations.