Toward Understanding Polycrystalline Aggregate Structure: Analysis of a Twin Intersection and the Interactions between Interfaces in Diamond

We provide a detailed description and discussion of the interactions between two narrow twins in diamond. It is shown that lattice displacements result from such interactions in many cases, and for narrow twins these can correspond to large strains that alter the balance of energies leading to the equilibrium interfacial structure. The accommodation of these strains and the modes of relaxation of the incompatible interfacial structures are discussed. It is shown that there are several modes of relaxation of the triple junctions that can interact with each other in a rich variety of ways, leading to several structural degrees of freedom.