Coherency dislocations in grain boundaries

Although coherency dislocation has been proposed for several decades, it is not yet accepted or even well known in the previous studies about grain boundaries. Here direct atomistic simulations are specially designed to prove the existence of coherency dislocations in grain boundaries. Our data show that coherency dislocations possess their own displacement and stress fields as conventional dislocations. In contrast to the prevailing model of grain boundaries with anti-coherency dislocations only, we support that coherency dislocations must be considered together with anti-coherency dislocations to provide a correct description of boundary structures and related phenomena.