Molecular dynamics and thermodynamic simulations of segregation phenomena in binary metal nanoparticles

Reconciling structure prediction of alloyed, ultrathin nanowires with spectroscopy

“…It has been reported that segregation within nanostructures can be caused by factors, related to surface energy, size, strain effects, and charge transfer between atoms. 74,75 There are likely no strain effects, which lead to the apparent segregation within Au 1 Ag 1 , because the lattice constants for Ag and Au are very similar. Moreover, charge transfer between Au and Ag would favor mixing between the two elements, a scenario which would have reduced the tendency of Ag to selectively segregate at the surface.…”

Synthesis of anisotropic Cu2−xS-based nanostructures by thermal oxidation

“…However, strong dependence of thermal behavior on material size and morphology, especially in nanoscale, is a cause of renewed research focused on this subject [20,28,29]. The prospect of patchy structures formation during thermal oxidation leaves very exciting and promising way of achieving nanostructures with unique properties and variety of applications in complex processes [30,31].…”

Factors of the Stability/Instability of Bimetallic Core–Shell Nanostructures

“…As the temperature grew, the shell of Au atoms gradually became thinner, and only at temperatures exceeding the macroscopic melting point of Au (1360 K) did the core-shell structure transform almost completely into binary Au-Co nanoparticles with uniform distributions of components. The gradual reduction in the thickness of the Au shells correlates with a notable drop in the surface segregation of Au, which was predicted by both atomistic and thermodynamic modeling [5,12,13]. The behavior of the Au 2500 @Co 2500 system turned out to be more complex (Fig.…”

“…Like the Co@Au and Au@Co structures, the Cu@Ni and Ni@Cu nanostructures correspond to when the components of binary metal nanoparticles differ notably in their bonding energies [14], and thus in the surface tension in both the liquid and solid states [15]. For such nanoparticles, the thermodynamic theory [5,12,13] predicts pronounced surface segregation of the component with lower surface tension (i.e., Au in binary Au-Co nanoparticles and Cu in Cu-Ni nanoparticles). For nanostructured Cu-Ni polycrystals, the thermodynamic modeling in [16] also predicted Cu segregation to grain boundaries, which agreed with the experiment in [17].…”