Hyperdislocations in misfit dislocation networks in solid films

A theoretical model is suggested which describes a new type of topological defect in condensed matter, namely the hyperdislocations in networks of misfit dislocations at film/substrate interfaces. Formulae for elastic characteristics of misfit dislocation (MD) networks with hyperdislocations, such as elastic moduli and the hyperdislocation energy, are found. With these formulae, the anisotropy of the MD networks and the dependence of the hyperdislocation energy on the film thickness are analysed.