An angle-resolved UPS study of the oxygen-induced reconstruction of Cu(110)

Abstract

Angle-resolved ultraviolet photoemission spectroscopy (ARUPS) has been used to study the p(2×1) oxygen-induced reconstruction of Cu(110). While there is agreement between experimental groups that the O atoms sit in the long-bridge site along the 〈001〉 Cu directions, there are two proposed models for the reconstruction: the missing-row model, in which alternating 〈001〉 rows of Cu atoms are missing, and the buckled-row model, in which the O-containing 〈001〉 rows are displaced outwards from their bulk position. Our ARUPS data show oxygen-induced changes in the Cu d-band photoemission features that are inconsistent with the missing-row model, thus favoring the buckled-row picture. In addition, the O–Cu bond appears to be highly directional and oriented along the 〈001〉 Cu rows, consistent with O sitting in the long-bridge site. Moreover, the O–Cu bond is primarily a result of the O(2pxy)–Cu(3dx2−y2) interaction.