Examples of crystallization of glasses and of the condensation of excitons to form an electron-hole liquid in germanium are used to study the kinetics of nucleation of a new phase. There are considerable advantages in tackling such model systems rather than other systems undergoing a first-order phase transition. Attention is drawn to two different nucleation regimes: transient and quasisteady-state. Special consideration is given to nucleation in an open system from which nuclei of the new phase may be removed rapidly as a result of diffusion or drift to absorbing walls. In such cases very strong supersaturation may be reached and the threshold of the appearance of a new phase may be independent of temperature.

@article{Fishman:1988,
	author = {I. M. Fishman},
	title = {Steady-state and transient nucleation of a new phase in a first-order transition},
	publisher = {Physics-Uspekhi},
	year = {1988},
	journal = {Phys. Usp.},
	volume = {31},
	number = {6},
	pages = {561-576},
	url = {https://ufn.ru/en/articles/1988/6/f/},
	doi = {10.1070/PU1988v031n06ABEH003567}
}