Correlations between one-dimensional structures at the Si(557) : Au surface

The quasi-one-dimensional structures at the Si(557):Au surface are examined by scanning tunneling microscopy at room temperature and at low temperatures (77 K). A short-range structural correlation between adjacent chain and row structures—attributed to Si adatoms and Si step edges, respectively—located on the same terrace is found. This correlation is absent between chains and rows located on adjacent terraces, demonstrating the decisive role of the step edge preventing correlations perpendicular to the chains. In addition, the temperature-dependent variation of the image contrast does not yield evidence for an increase of the structural unit cell of the one-dimensional structure as would be expected for a Peierls transition.