Low temperature InSb(0 0 1) surface structure studied by scanning tunneling microscopy

InSb(0 0 1) surface prepared by ion sputtering and thermal annealing has been studied in the temperature range from 77 K up to 300 K using scanning tunneling microscopy (STM). At 300 K the surface is c(8 × 2) reconstructed as indicated by low energy electron diffraction and STM images, and its structure appears to be consistent with the “ζ-model” recently proposed for this surface. Upon lowering of the temperature below 180 K a new phase appears on the surface. This phase is characterized by the surface structure period doubling along [1 1 0], lowering the surface symmetry from c2mm to p2, and appearance of structural domains. Possible origins of the new phase are discussed.