PREFERRED [111] GROWTH OF ZNSE CRYSTALS FROM THE VAPOR DUE TO REPEATED TWINNING

ZnSe crystals develop preferably {1 1 0} faces. When three adjacent fa ces, e.g. (1 1 0)(H), (1 0 1)(H) and (0 1 1)(H) form a corner an ortho -twin is frequently generated at that particular tip. The (1 1 1) twin ning plane provides the initially hat twin with steps over the {1 1 0} (twin), side faces so that again a three-sided pyramid appears with a decreasing(1 I 1) top face. In contrast to the usual twin-induced [1 1 2] growth, the repeated twinning on the pyramid vertex leads to a pre ferred [1 1 1] growth.