Dissociation of misfit and threading dislocations in Ba0.75Sr0.25TiO3 epitaxial film

Ba0.75Sr0.25TiO3 film was epitaxially grown on a (001) LaAlO3 substrate using single-target pulsed laser deposition. The dissociation of misfit and threading dislocations in the epitaxial Ba0.75Sr0.25TiO3 film was investigated using high-resolution transmission electron microscopy (HRTEM). For a misfit dislocation with a Burgers vector of [200], it was shown that it could dissociate into four partial dislocations with Burgers vector of type 1/2 < 110>. For the threading dislocations, it was found that they usually coexist with stacking faults. The formation mechanism for the dissociated dislocations was discussed. All the dislocations can relieve the local strain in the Ba0.75Sr0.25TiO3 epitaxial film.