Variable Stoichimetry Surface Reconstructions: New Models for GaAs(111) (2x2) and the square root of 19

摘要

The (111) surface of GaAs exhibits three stable reconstructions. Two are (2 x 2), As stabilized and Ga stabilized respectively, and the third is (the square root of 19). Transitions between these structures are obtained by variation of the experimental conditions. New models are proposed for all of the above reconstructions, based on ab initio total-energy calculations and experimental information regarding composition.