Splitting of the phase diagram of a stratified solid solution in micro- and nanosized systems

Conditions for the formation and existence of stable and metastable thermodynamic states in a system with phase transformations have been considered. As the system decreases to nano- and submicron sizes, the degeneracy of the phase diagram in stratified mixtures is removed, due to which images of phase equilibria in the diagram has variants that substantially differ from the diagram of a macroscopic system by critical stratification temperatures, composition of coexisting solutions, and region of existence of metastable phases. This size effect is considered using the example of phase transformations in the Bi–Sb solid solution.