Spin- and k-dependent electronic structure of ferromagnetic nickel

Abstract

We have measured the spin- and angle-resolved photoemission spectra of ferromagnetic Ni(110) and determined the spin-dependent energy-dispersions along the Γ-K-X direction of the Brillouin zone. We have observed the exchange-split band dispersions and assigned the bands to s -like Σ 1 band and d -like Σ 1 , Σ s and Σ 4 bands in Γ-K region and S 1 , S 2 and S 4 bands in K-X region. Comparing the observed results with the theoretical LDA band calculation, we found that the width of d -band is narrower than the calculated band width. The narrowing in the majority spin band is larger than in the minority spin band. It is shown that the electron correlation in the majority spin band is much stronger than in the minority spin band. We also found that the observed values of the exchange splitting are much smaller than the calculated values.