Study of the Effects of Different Factors on Crystal Growth from Solution: Data of Atomic Force Microscopy

Abstract

In order to crystallographically reconstruct the growth processes of mineral crystals and to establish fundamental patterns in crystal growth at a nanoscale, the effects of various factors on the characteristics of layer-by-layer crystal growth from solution were modeled using atomic force microscopy (AFM). In an experiment on growth in the area of a scratch, it was shown, using an original method of AFM data processing, that the average rate diagrams indicate a situation of a self-organization process: stable auto-oscillations in the growth rate. Comparison of the results with data on the growth of similar uninfluenced hillocks leads to the conclusion that giant fluctuations and the phenomenon of simultaneous growth and dissolution in local areas are caused by nanoindentation, when the strain from artificially formed defects strongly influences the evolution of the surface. In an AFM experiment on the trapping of foreign solid particles by a growing crystal at the nanoscale, the process of formation of a screw dislocation initiated by a foreign inclusion particle was registered. To theoretically explain the process, a three-stage mechanism is proposed that involves strain relaxation around the inclusion particle by the formation of one or more dislocations prior to the sealing of the inclusion during the first stage, the attachment of edge dislocations to them during the time of overgrowing in the second stage, and the development of a resulting dislocation after the particle has been completely sealed during the third stage. In studying growth in a flow cell, the mechanism of nanoscale reorientation of the growth hillock in the direction of the flow was established at a nanoscale, and the phenomenon of a change in the dominant hillock was registered. The resulting dissolution patterns in the channel are a clear demonstration of Curie’s Symmetry Principle, according to which only those symmetry elements of a body in an environment can be preserved that are shared by the body and the environment.