Abstract

The valence-band electronic structure of a clean Ni(111) surface is investigated by spin-resolved photoemission. At room temperature the orientation of the photoelectron spins on the Bloch sphere and the exchange splitting of surface and bulk states along the surface normal (Γ̅ ) are determined. All investigated states are found to have a sizable exchange splitting >50 meV. Since the splitting is smaller than the intrinsic line width in the spin-integrated spectrum this is only seen with a spin-resolved technique. At room-temperature photoemission reaching above the Fermi level directly shows that the Shockley type surface state S1 has an occupied majority and an unoccupied minority band with a splitting ΔEex=62±15 meV. The surface states below the Fermi energy show a larger exchange splitting for in-plane hybridization [ΔEex(S3)=160 meV] than for out-of-plane hybridization [ΔEex(S2)=55 meV].