HIGH-RESOLUTION ANGLE-RESOLVED PHOTOEMISSION FROM CU(610)

Cu(610) has a mean terrace width of six atoms. Although the regular ar rangement of steps a as verified by SPALEED, no step-induced surface u mklapp process could be identified in UPS spectra taken with HeI radia tion. This fact allows an easy comparison with results from Cu(100). I n particular, we demonstrate that the final state wave vector can be d etermined. by triangulation using exclusively the Cu(610) surface, sin ce equivalent k-space points contribute at different electron emission angles. However, spectra from equivalent points exhibit differences i n the UPS linewidth and this gives additional information on the final slate lifetime. Finally we discuss the modification of a Tamm state [ its analogue is observed at (M) over bar on the (100) surface] due to confinement by the steps. (C) 1998 Elsevier Science B.V.