Observation of a Λ1-symmetry surface state on Ni(111)

An s-p-like intrinsic surface state on Ni(111) has been found which has an energy of Ei=-0.25 eV relative to the Fermi energy at Γ̄ and lies between the L3 (Ei-0.15 eV) and L2′ (Ei=-0.9 eV) bulk states. Its momentum dispersion (E vs k→) and hν-dependent photoionization cross section have been determined using angle-resolved photoemission with synchrotron radiation. The existence of this state significantly affects spin-polarized photoemission, chemisorption, band-structure, and exchange-splitting interpretations for Ni. © 1978 The American Physical Society.