A TEMPERATURE STUDY OF MIXED AGBR-AGBRI TABULAR CRYSTALS

The results of a temperature study of AgBr-AgBrI(10%I) tabular core-sh ell microcrystals are presented. Stacking faults, which are present in the shell of the microcrystal, are found to disappear upon heating th e microcrystals to 200 degrees C and higher. A model for the disappear ance of these stacking faults, involving the movement of partial dislo cations in the stacking fault plane, is presented. Stacking faults are observed to be removed most easily from parts with only one reentrant angle at the twin planes, i.e., in hexagonal microcrystals or at the long segments of triangular microcrystals.