Phase transitions, crystal growth

Thermodynamic stability and pathways for the formation of core-shell states in stratified systems of small volume

V. B. Fedoseev

G. A. Razuvaev Institute of Organometallic Chemistry, Russian Academy of Sciences, Nizhny Novgorod, Russia

Abstract: Size effects during phase transitions in a binary stratified mixture in a small volume are simulated using chemical thermodynamics methods. The results are describing the conditions for the existence of stable, metastable and unstable thermodynamically equilibrium states using the example of a Bi–Sb solid solution. An energy surface has been created that displays all states of a stratified solution in a system with a core-shell structure. Energy profiles for optimal pathways between homogeneous and heterogeneous equilibrium states are shown. Critical nucleus states are identified. As the volume of the stratifying solution decreases, the homogeneous state becomes metastable and its stability increases. At the same time, heterogeneous states lose stability, become metastable and disappearated. The composition of the mixture also affects the energies of formation and stability of heterogeneous states.

Keywords: phase transformations, size effect, stratifying solutions, metastable states, critical nucleus.

Received: 03.10.2024
Revised: 04.10.2024
Accepted: 05.10.2024

DOI: 10.61011/FTT.2024.11.59338.252

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