Observations of island formation

The role of elastic interactions in influencing island shape transitions 

7s of the growth surface. In the process of coarsening, islands increase the amount of the area with surface energy 7s and decrease the amount with surface energy 7f, which represents a net increase in surface energy of the system. Yet another limitation on island size is that mass transfer from one island to another is very restricted, so that the material available for incorporation into each island is about the same as for any other island. 

In the study of surface stability in Section 8.4.1, it was shown that the flat surface of a strained elastic solid is unstable under small amplitude 

Consider the chemical potential expression (8.137) for the special case when the surface energy density Us depends on orientation 9 but not on surface strain e. Verify that the chemical potential expression reduces to x = f/ — n Us 4- Dg), where the prime denotes differentiation with respect to 6. The quantity in parentheses is sometimes called surface stiffness its existence presumes the function Us 9) is indeed twice differentiable. 

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