Model of mismatched contact for dislocation generation during coalescence of grains

Dislocations may be generated during the coalescence of epitaxial islands and grains in crystal growth by oriented attachment. Since the attaching grains may be mismatched in terms of their lattices, adhesive contact mechanics with strain mismatch has been adopted to investigate the generation of dislocation loops during coalescence via an energy approach. Results have demonstrated that for a given strain mismatch, there exists a critical grain size only above which can dislocations be generated and, the larger the strain mismatch, the smaller the critical grain size. Implications of the results are discussed.