Segregation of Pure B at the Internal Surface

We can see from the results of Model 2 and Model 3 that, with decreasing internal radius, the segregation of the fast-diffusing atom B increases. Sooner or later, it can exceed the homogeneity range of the intermediate phase, which could lead to precipitation of the almost pure B-phase at the internal surface. Formally, to conserve the spherical symmetry, after the precipitation, the nanoshell should consist of two subshells - pure B inside and inhomogeneous IMC outside. Thus, 

The decrease in the internal radius, simultaneously with increasing segregation, causes the shift of the equilibrium boundary concentration of B inside IMC at the curved interface between B and IMC. Let us compare these two equilibrium concentrations. According to Gibbs theory, at curved interfaces, the mentioned shift is equal to 

On the other hand, according to Equation 7.44, even for a diffusivity of A tending to zero, the segregation at the internal boundary is less than 

Kinetic Monte Cario Simulation of Shrinkage of a Nanoshell 

The analyses presented in the previous paragraphs are purely phenomenological and do not take into account the possible pecuharities of diffusion and structure 

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