Transport, Nucleation and Growth
Part of the
Updates in Applied Physics and Electrical Technology
book series (UAPE)
Most crystal growth processes involve the following steps:
Transport of reactants to the growth surface (in some cases via a “boundary layer” adjacent to the surface).
Adsorption at the growth surface
Nucleation (irreversible location on a crystal lattice site)
Growth (advance of the liquid-solid or vapour-solid interface)
Removal of unwanted reaction products from the growth surface
These are illustrated schematically in Figure 2.1. The driving force for crystallisation is the supersaturation of the gas or liquid phase with respect to the component whose growth is required. Too little supersaturation will result in an unacceptably slow growth rate. At the other extreme of the supersaturation range the rate of condensation exceeds the rate at which the atoms or molecules can be incorporated onto the crystal lattice, leading to breakdown of the single-crystal interface and the onset of non-uniform cellular or dendritic growth (see Chapter 3). The object of good crystal growth is therefore to achieve and maintain a constant level of supersaturation within this range.
KeywordsGrowth Surface Linear Growth Rate Solutal Boundary Layer Ledge Growth Surface Diffusion Coefficient
© Springer Science+Business Media New York 1987