Transmission electron microscopy studies of (111) twinned silver halide microcrystals.

The present paper covers the results of different transmission electron microscopy studies on silver halide microcrystals. Pure AgBr as well as core-shell AgBr-AgBrI crystals are investigated. In the former parallel and non-parallel twinning modes yielding tabular and needle- or tetrahedral-shaped microcrystals, respectively, are discussed. Also the short-range-order of Ag+ interstitials around the twin planes as determined from diffuse intensity in reciprocal space is described. The latter yields a technique to determine the variant in which dislocations are located in certain core-shell microcrystals. The introduction of iodine also results in the presence of inclined stacking faults in the shell and of long-range iodine ordering on the crystal surface.