Abstract
The scanning tunneling microscope (STM) has been used to study the c(8×2) reconstruction of GaAs(100). High-resolution STM images imply this surface is composed of equal numbers of arsenic and gallium atoms, resolving disagreements in the interpretation of several previous experiments. The c(8×2) structure arises from an ordered arrangement of (4×2) subunits, with each subunit containing two As dimers and two Ga dimers. © 1993 The American Physical Society.