The role of chemical potentials in surface reconstructions was examined and shown to be crucial for binary semiconductor surfaces such as GaAs(111)-(2 x 2). It was predicted that, under As-rich conditions, a new model - the As triangle - was the lowest-energy geometry whereas the Ga-vacancy model was appropriate for Ga-rich conditions. A change in the relative chemical potential of Ga and As was expected to produce a phase transition between the two structures.

Role of Chemical Potentials in Surface Reconstruction - a New Model and Phase Transition of GaAs(111)2 x 2. E.Kaxiras, K.C.Pandey, Y.Bar-Yam, J.D.Joannopoulos: Physical Review Letters, 1986, 56, 2819-22