Investigation of mechanisms of the crystal growth process (Kossel model)

Abstract

The object of this research is the mechanisms of crystal growth processes. As a model of investigation, a plane-faced crystal in the form of cubes is taken. Two mechanisms of crystal growth are investigated. With the first mechanism in the process of crystal growth, the growing surface moves due to the lateral displacement of the steps, while the second one – a continuous displacement along the normal to the surface of the crystal occurs. A problematic issue when growing crystals with these mechanisms from the melt is the preservation of the purity of the metal itself, especially if it is in a molten state. It is shown that when using the «layer-by-layer» mechanism of crystal growth, the problem of the formation of two-dimensional «embryos» is a problematic moment. This process is quite sensitive to supersaturation, and the probability of its carrying out at rates below 45–50 % is quite small. In the course of the research, statistical analysis methods are used to determine the positive and negative aspects of the use of crystal growth mechanisms, analyze the results of studies to determine the dynamics of the use of a particular mechanism for growing crystals. The hypothetical-deductive method is used in the process of acquaintance with the actual material of research in the field of crystal growth, which additionally requires in-depth analysis of information sources and also a method of generalizing the results to establish the general properties and trends characteristic of the crystal growth mechanisms under study. It is justified that if the thermal conditions of the processes are not observed, it is difficult to achieve the desired orientation and configuration of the crystals. It is shown that the «normal» crystal growth mechanism is effective provided that the condition that there are enough «energetically favorable» sites for fixing the atoms on the surface, which is not always feasible.