A fast computational method for determining equilibrium concentration profiles in intermixed nanoislands

An efficient computational method for finding the equilibrium concentration profiles which minimize the free energy of intermixed heteroepitaxial islands of assigned shape and average composition is described. A combination of a Monte Carlo method and continuum elasticity theory solved by a finite element method is shown to provide the desired profiles allowing for a significant computational gain with respect to atomistic approaches. The role played by dimensionality (ridges versus islands) and by entropy is discussed.