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Free keywords:
Chemisorption; Biological molecules – proteins; Surface structure; morphology; roughness; topography
Abstract:
Suggestions that homochiral ordered phases of glycinate, NH2CH2COO–, may exist on Cu(1 1 0) and Cu(1 0 0) have been evaluated in the light of experimental evidence from scanning tunnelling microscopy (STM), qualitative low energy electron diffraction and scanned-energy mode photoelectron diffraction. There is clear evidence for heterochiral Cu(1 1 0)(3¥2)pg and Cu(1 0 0)(4¥2)pg phases. All proposed models for a homochiral (3¥2) phase on Cu(1 1 0) are inconsistent with the results of at least one of the experimental studies. A coexistent c(4¥2) homochiral phase on Cu(1 0 0) cannot be excluded on a similar basis. However, the only evidence for such homochiral phases, obtained from STM, may be attributed to an experimental artefact associated with an asymmetric tunnelling tip.