Nanoscale crystal growth processes triggered by captured solid impurity particles

Abstract

Atomic force microscopy (AFM) was used to study the influence of solid neutral particles on dynamics and kinetics of surface growth on nanoscale. The experiment involved real-time observations of the hydroxymethylquinoxalinedioxide (C10H10N2O4) surface capturing micrometer tourmaline particles of no particular shape and with low adhesiveness to the material of the host crystal. It was made possible to visualize in detail a hillock formation on a screw dislocation triggered by a captured particle, as well as dislocation propagation through the overgrowing macrostep.Out of the multitude of similar size particles, only one of them generated a long-term screw dislocation – that was the particle in whose area a Frank-Read dislocation had been triggered even before the particle cavities were sealed. A detailed scanning showed that the wellknown phenomenon of a dislocation propagating through the overgrowing layers manifests itself as creation of a new screw hillock with monomolecular steps exactly above the lower hillock axis.The author’s method of statistical processing of AFM data was used to compile an array of average tangential and average normal growth rates and their fluctuations. In spite of the matter in the solution not being refilled, the normal and tangential rates showed constant and significant increase.The results were compared with the data from several earlier experiments with and without special impact during the growth process. It was established that the growth rate in the experiment with incorporation of impurities has small and almost stable fluctuations just like in the experiments without any impact.