The 2 x 1 π-bonded chain reconstruction of cleaved Si(111) was observed on sputtered and annealed Si(111) surfaces after thermal quenching. Several terraces of 2 x 1 comprising all three principle domains were seen in a region ≈2000 x 700Å2, non-contiguous with domains of 7 x 7 reconstruction that surround the 2 x 1 area. Phase boundaries between 2 x 1 domains were observed both on terraces (intra-terrace) and between terraces (inter-terrace) at double-layer step transitions. I-V characteristics acquired over the 2 x 1 terraces show good overall agreement with previous work, but differ by 0.1 to 0.4V in the energy position of features in the normalized differential conductivity. This could be due to the variability in electronic structure for typical high-resolution tunnelling tips, bringing into question the use of such tips for electronic-structure analysis. The presence of this phase on an otherwise 7 x 7 surface was interpreted in terms of thermal-stress cleavage of the sample during the quench.

Anomalous Surface Reconstruction - Observation of Si(111) 2 x 1 on Sputtered and Annealed Si(111) Surfaces. R.S.Becker, T.Klitsner, J.S.Vickers: Physical Review B, 1988, 38, 3537-40