Lack of evidence for intrinsic surface states in Ni and Cu

Surface states on d-band metals have recently been studied by Forstmann and co-workers. They have reported that such intrinsic surface states explain peaks in the density of states seen in photoemission from Ni and Cu. We summarize recent photoemission and ion-neutralization data which indicate that no evidence for such states has as yet been found experimentally. © 1971 The American Physical Society.