The atomic structure of the dislocation cores in a small-angle grain boundary in BaTiO₃ thin films

The atomic structure of the cores of the dislocations forming a [110] tilt boundary of 10° misorientation in a BaTiO₃film is characterized by means of focal-series reconstruction. Along the small-angle grain boundary, facets with different inclinations are accompanied by different types of dislocation. The dislocation with a Burgers vector_of a[001] appears as a perfect edge type. Those with a Burgers vector of a[111] are dissociated into three partials with a Burgers vector of (a/3) [111], leading to two segments of stacking faults. Structural models of these dislocation cores are suggested on the basis of the phase of the reconstructed wavefunction and tested by simulation of the wavefunction.