Comment on ‘‘Structure of the Mn-induced Cu(100) c(2×2) surface’’

We have studied the atomic arrangement of Mn upon deposition on Cu(100) at room temperature using low-energy electron diffraction (LEED) and scanning tunneling microscopy (STM). Scanning tunneling microscopy reveals that Mn is already incorporated at very low coverages (∼0.005 ML Mn). Both LEED and STM show that the surface alloy is characterized by a considerable corrugation where Mn atoms are displaced outside by 0.30 Å. Our findings are at variance with a recent STM study [Phys. Rev. B 52, 2735 (1994)] which reports a corrugation of approximately 0.12 Å and claims Mn incorporation only above a critical Mn coverage which should be larger than 0.06 ML. © 1996 The American Physical Society.