Step and Kink Dynamics in Inorganic and Protein Crystallization

Abstract

Revived interest in crystal growth from solutions is driven by a variety of demands, including the need to develop an understanding of biomineralization processes in bones, teeth, and shells; and efforts to characterize large optically nonlinear crystals, perfect crystals of proteins, nucleic acids, and complexes such as viruses. Producing and purifying drugs, food, paint, fertilizers, and other polycrystalline materials in industry are other expanding areas that rely on crystal growth from solution. These general practical incentives have activated in-depth studies that revealed new phenomena and raised new fundamental questions: Are thermal fluctuations of steps on a crystal face always fast enough to assure the step propagation at the rate controlled just by molecular incorporation at kinks? Is the Gibbs–Thomson capillarity shift of thermodynamic equilibrium always applicable to evaluate the crystallization driving force of polygonized steps? Is it possible to eliminate the step bunching on a growing crystal face that compromises crystal homogeneity, or at least to mitigate it? In this overview, we will discuss experimental findings and provide state-of-the-art answers to these questions.