One More Parameter Determining the Stratification of Solutions in Small-Volume Droplets

Fractal Nanoparticles of Phase-Separating Solid Solutions: Morphology-Dependent Phase Equilibria in Tungsten Heavy Pseudo-Alloys

“…At "higher" temperatures, at the same time, mechanism 1 ("volume-controlled segregation") is realized while the tungsten content is increased in the shell-phase. If the nanoparticle morphology becomes more complicated (i.e., the fractal dimension of a nanoparticle is reduced) at any temperature in state 1, the realization of mechanism 2 manifests itself (in more detail, the "competition" between the mechanisms of reducing the free energy is discussed in [16,17,19]). In the Fig.…”

“…In small-volume systems, in their turn, not only the volume fractions but also the compositions of core-and shell-phases (and co-existing phases in the most general case) at equilibrium depend on the initial composition. This effect is generic for nanoscale structures, being explained by the realization of different mechanisms of lowering the free energy of the system in the case of nanoparticles of different compositions (see [17,19] for more details).…”

“…I A = 30202.0; II A = 2635.5; III A = 0 [9,15]. The energies of interface boundaries are calculated using the first approximation (this approach and the obtained results are not accompanied by any losses of generality, see also [17,19]):…”

“…At the same time, in the analysis of phase equilibria in systems of a small volume, it is necessary to take into account several characteristic features. These peculiarities manifest themselves in significant dependences of mutual solubilities of components and equilibrium volume fractions of coexisting phases on the volume [9][10][11][12][13][14][15][16][17][18][19][20], shape of a nanoparticle [12][13][14]18], thermodynamical characteristics of the surrounding environment [20] and several other factors [15,17,19]. The equilibrium phase compositions of small-volume systems are significantly different from the phase compositions of the same systems in the bulk state and can be modeled using the methods of equilibrium chemical thermodynamics [21] and several other approaches [22] (the applicability of thermodynamical methods in the analysis of phase equlibria in small-volume systems as well as their applicability limits are discussed in [23]).…”