  This paper compares two approaches for investigating the near-surface
composition profile that results from surface segregation in the so-called
Cantor alloy, an equi-molar alloy of CoCrFeMnNi. One approach consists of
atomistic computer simulations by a combination of Monte Carlo, molecular
dynamics and molecular statics techniques, and the other is a nearest neighbor
analytical calculation performed in the regular solution approximation with a
multilayer model, developed here for the first time for a N-component system
and tested for the 5-component Cantor alloy. This type of comparison is useful
because a typical computer simulation requires the use of ~100 parallel
processors for 2 to 3 hours, whereas a similar calculation by means of the
analytical model can be performed in a few seconds on a laptop machine. The
results obtained show qualitatively good agreement between the two approaches.
Thus, while the results of the computer simulations are presumably more
reliable, and provide an atomic scale picture, if massive computations are
required, for example, in order to optimize the composition of a multicomponent
alloy, then an initial screening of the composition space by the analytical
model could provide a highly useful means of narrowing the regions of interest,
in the same way that the CALPHAD method allows rapid investigation of phase
diagrams in complex multinary systems.
