Asymmetric Cracking in III–V Compounds

Experimental evidence for unidirectional cracking in III – V compounds is presented. The crack direction is shown to be a function of the sign of the applied stress and follows the asymmetry of the zinc blende structures. The critical stress for cracking in in tension was found to be . Cracks in and grown on substrates are related to the zinc blende asymmetry with the aid of Sirtl's etch. A fracture mechanism which introduces asymmetric dislocations into the Cottrell fracture mechanism is advanced. Asymmetries in elastic bending and cross‐hatch patterns are discussed. The question of glide vs. shuffle dislocations is also considered.