In this study, Au@void@AgAu yolk-shell nanoparticles with different shell compositions were investigated by molecular dynamics simulation. Various Ag mole fractions in the shell of nanoclusters were considered. The results indicated that sizes of these nanoparticles play the key role in their thermodynamic stability, in such a way that the ratio of external radius to the thickness of the shell region should be decreased enough to reach a thermodynamic stability at room temperature. For small nanoparticles with large ratio of external radius to the thickness of the shell region, collapse of the shell leads to complete filling of the void space and creation of the more stable Au@AgAu core-shell or mixed nanoclusters. Hence, they are not stable at room temperature. (C) 2018 Elsevier B.V. All rights reserved.