Strong effect of substrate symmetry and pre-patterning on self-assembly of compositional patterns

First-principles-based computer simulations are employed to elucidate the effects of substrate symmetry and externally applied “potentials” on directing self-assembly of highly ordered nanoscale patterns. We focus on alloy films as a specific example where the energetics underlying composition modulation can be accurately quantified. We demonstrate that even relatively weak external potentials, with periodicities considerably larger than the intrinsic composition modulation wavelengths, can be highly effective in stabilizing ordered compositional patterns at the nanoscale.