The first reported observations were made of the reconstruction of semiconductor surfaces at atmospheric pressure. By using reflectance-difference spectroscopy, it was shown that the primary reconstructions which occurred on (001) GaAs under ultra-high vacuum conditions also occurred under atmospheric pressures of H2, He or N2. The results showed that dimer formation was not limited to surfaces under ultra-high vacuum.

I.Kamiya, D.E.Aspnes, H.Tanaka, L.T.Florez, J.P.Harbison, R.Bhat: Physical Review Letters, 1992, 68[5], 627-30