The {111} surfaces were examined by using scanning tunnelling microscopy, and soft X-ray photo-electron spectroscopy, and a comparison was made of the 3 different 2 x 2 reconstructions which were observed. It was found that both the (111)A and (111)B surfaces initially exhibited 2 x 2 ordered adstructures following thermal desorption of an As cap; although spectroscopy showed that they were chemically inequivalent. With increasing temperature, the (111)A surface developed into a Ga-vacancy 2 x 2 structure which was rather similar to a (110) surface. However, the (111)B surface lost its 2 x 2 periodicity with increasing annealing temperature, following a sequence of less As-rich structures.

J.M.C.Thornton, P.Weightman, D.A.Woolf, C.J.Dunscombe: Physical Review B, 1995, 51[20], 14459