Dislocation substructures in CO2-laser-sintered undoped BaTiO3 were investigated via transmission electron microscopy. Deformation of BaTiO3 at 1390C occurred when the slip system of <100>{001} was activated by the intrinsic thermodynamic driving force for sintering. Dissociation of dislocations with Burgers vector b1 = [001] into two collinear partials of b2 = ½[001] and b3 = 1/2[001] was identified unambiguously by using weak-beam dark-field imaging. Part of the b3 partial further changed to a scallop-shape half-loop of b3’ = ½[100] by a non-conservative loop formation mechanism of mixed climb and glide in the {111} plane. Results suggested that plastic flow by dislocation mechanisms contributed to the densification of BaTiO3 at 1390C. It took place via a climb-controlled glide mechanism, which was rate-determined kinetically by the lattice diffusion of Ba2+.

Collinear Partial Dislocations in Barium Titanate Perovskite. M.H.Lin, H.Y.Lu: Materials Science and Engineering A, 2002, 333[1-2], 41-4