Nanoscopic investigations on the surface topography, defect-substructure, dislocations and micromorphology of surfaces of BaxSr1−x(NO3)2 mixed crystals

Experimental investigations on the defect-substructure, dislocations and micromorphological features of the surfaces of mixed crystals of BaxSr1−x(NO3)2 have been reported. Variations in the micromorphological features have been studied over a whole composition range. Morphology of these crystal surfaces, as investigated by Atomic Force Microscopy (AFM), is found to depend mainly on the degree of supersaturation, concentration of Ba2+/Sr2+ ions in solution and growth temperature. Observations of growth spiral in concurrence with height of hillocks revealed the existence of screw dislocations that led to the proposition of two dimensional nucleation of crystal growth process. Observation of coalescence of neighbouring growth spirals displays the Frank-Read mechanism in the growth process.