GaAs (001) - (4x2) Rekonstruction

The (4x2) surface is the gallium richest surface with a known structure. The gallium coverage is 0.75 monolayer, no arsenic is fond on this reconstruction. The RAS-spectrum is dominated by the feature of the gallium-dimers at about 2eV.


RAS spectrum of a (2x4) during MBE [Hingerl93]

STM-images are often of low quality, due to rapid degradation of the scanning tip. There are two possible structure, with one and two gallium dimers in the uppermost layer. Several investigations have confirmed the model below:


This is the model from STM measurements of the (4x2) prepared by MBE [Biegelsen90].

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last changes: 12.12.1996