New ideas in the theory of crystal nucleation (review)

More or less coherent picture of crystal nucleation for over 100 years has recently been revised fundamentally. Various models of nonclassical crystal nucleation and growth appeared, which were particularly based on the assumption of the existence of stable prenucleation clusters.We considered in detail the properties of special prenucleation clusters, referred to as clusters of “hidden” phase or quatarons. The dynamism of the structure, its fluctuating external form and surface, the oscillating nature of the bonds between atoms, the relatively high proportion of surface atoms, as well as the impossibility to neglect quantum effects in their behavior and a number of other unusual properties make the prenucleation clusters unique formations, a special form of structural organization of matter at nanolevel. Such clusters for a long time retain the ability not to “fall” into the global energy minimum with fixed bonds. Uncertainty in the arrangement of atoms remains until the chemical bonds between them are completely established. After that, the characteristic structurelessness disappears, and they are transformed into other forms of nanoparticles, including crystalline nuclei.The comparative characteristics of various non classical crystal nucleation schemes is given. The importance of studying quatarons and other objects of the protomineral world for the development of non classical ideas in the theory of crystal nucleation is pointed out. It is assumed that experiments to study the processes of interaction of atoms with the formation of pre-nucleation particles and their crystallization can be carried out on the European X-ray Free Electron Laser.