AFM STUDY OF ETCHING OF CLEAVED (100)-FACES OF L-ARGININE PHOSPHATE MONOHYDRATE SINGLE-CRYSTALS .1. DISLOCATION ETCH PITS AND STEP BUNCHING

The formation of dislocation etch pits and the process of coalescence of dissolution steps composing the walls of dislocation etch pits on t he etched {1 0 0} cleavage faces of L-arginine phosphate (LAP) single crystals was studied by using atomic force microscopy (AFM). The resul ts show that(1) etch pits at edge and screw dislocations are formed by repeated two-dimensional nucleation mechanism, (2) the values of diff erent slopes of etch pits in regions close to dislocation lines are du e to differences in the stress fields of dislocations producing the et ch pits, and that (3) the process of step bunching is statistical in n ature.