Crystallization (and by extension nucleation) is a critical process in all material systems that determines how a material will form. Manufacturers have generated billions of dollars of economic development by creating new materials through manipulation of crystallization.

There are two phenomenological steps in the process of phase transformation from a supercooled liquid to a crystal: a nucleation step and a crystal growth step. The growth step is described well by Wilson-Frenkel’s theory,¹ but the underlying physics of nucleation remains elusive. For glass-ceramics, or composite materials consisting of crystals in a glassy matrix, having a clear idea of how nucleation occurs would aid significantly in finding the optimal thermal history for the desired crystallite distribution.