A [001](110) small-angle grain boundary SrTiO3 was studied by electron-energy-loss spectroscopy and high-resolution transmission electron microscopy. The a<110> grain boundary dislocations were dissociated into two partial dislocations involving climb of the partials. From their separation an upper limit of the (110) antiphase boundary energy of 720mJ/m2 was deduced. Electron energy-loss spectra were obtained from the partial cores and the antiphase boundary in a dedicated scanning transmission electron microscope. The Sr/Ti ratio was found to be increased in one of the partial cores but

decreased in the other. This could be understood from the dissociation mechanism. From the increase of the Ti/O ratio it was concluded that the dislocation cores were O deficient. Ti-L2,3 electron energy-loss spectra showed a reduction of Ti in the partial dislocation cores as well as a reduced crystal field.

Electronic and Atomic Structure of a Dissociated Dislocation in SrTiO3. Z.Zhang, W.Sigle, W.Kurtz, M.Rühle: Physical Review B, 2002, 66[21], 214112 (7pp)