Atomic force microscopy studies on liquid inclusions and induced defects of cadmium mercury thiocyanate crystal

摘要

Liquid inclusions and various defects accordingly induced on a nonlinear optical material of CMTC crystal were investigated by atomic force microscopy. Liquid inclusions are chiefly caused by formation of macrosteps, which result from impurity-induced inhibiting of step growth and meeting of step trains advancing along different directions. Liquid inclusions induce generation of dislocations and even cracks within the crystal by three-dimensional nucleation growth. Liquid inclusions also provide screw dislocation growth sources, leading to formation of spiral hillock trains with ridged tails. Etching experiments reveal circular hollow cores, indicative of screw dislocation growth, and negative crystals resulting from further crystallization in the liquid inclusions. [References: 17]