Dislocation Substructures in CO2-Laser-Sintered Barium Titanate

Abstract

The dislocation substructure in polycrystalline BaTiO3 pressureless sintered by a CO2 laser at 1390 °C has been investigated via transmission electron microscopy. It reveals that high temperature deformation occurs when the slip systems 〈10〉pc{110}pc and 〈001〉pc{100}pc have been activated by the intrinsic sintering stress. The dissociation of dislocations b1 = [001]pc occurs by the reaction [001]pc → 1/2 [011] + 1/2 [01]. The dissociated dislocations contain a series of scallop-shaped half-loop partials with Burgers vectors b3 = 1/2 [01]. The configuration of dissociated dislocations was developed by a mixed mechanism of climb and glide. The densification of the ceramics has been contributed by plastic flow facilitated by both climb and glide of the dislocations with Burgers vectors 〈001〉pc and 〈10〉pc. The dissociation plane appears to be (10)pc for the climb and glide mechanism.