The configurations of dislocations, in natural monocrystals with the perovskite structure which had been deformed by high-temperature creep, were characterized by means of transmission electron microscopy. Screw dislocations with Burgers vectors of [100] and [011], dissociated on the (011) plane, formed rectangular networks with extended 4-fold nodes in the shape of octagons. It was noted that such a configuration had never been observed in any previously investigated perovskite; except CaGeO3. Screw dislocations with Burgers vectors of [101] and [¯101], on the (010) plane, reacted to form a twist wall. Dislocations with a Burgers vector of [002], that were produced by the reaction, decomposed into 2 perfect [001] dislocations. This resulted in a previously unobserved configuration with 3-fold nodes at the corners of rectangles. Both the octagonal extended nodes, and junctions decomposed into perfect dislocations, were seen in samples that had been deformed by slip on {100} or {110} planes. They were observed only at temperatures above 1520K in the cubic phase.

Dislocations in CaTiO3 Perovskite Deformed at High-Temperature: a Transmission Electron Microscopy Study. P.Besson, J.P.Poirier, G.D.Price: Physics and Chemistry of Minerals, 1996, 23[6], 337-44