BRANCHING AND BENDING OF DISLOCATIONS IN SODIUM CHLORIDE CRYSTALS

Discrepancies arising in the number and positions of the etch pits on the opposite cleavage faces when cleavage takes place at different positions from the branching and bending points have been discussed. Experimental evidence for these discrepancies is presented by the help of a new etchant consisting of methanol as solvent and CdCl2 as poison developed for NaCl crystals. Using this etchant which has the unique property of producing etch pits associated with beaks at the aged dislocations, actual branching of dislocations occurring inside the crystal, shift in the positions of the corresponding etch pits on the opposite cleavage faces due to bending of dislocations near the cleavage plane, etch pits associated with wings, and solution channels arising due to dislocation half-loops have been recorded. © 1969 The American Institute of Physics.