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Abstract

A temperature-dependent study of the magnetic surface states on Ni(100) near the Fermi level reported by Plummer and Eberhardt [Phys. Rev. B 20 (1979) 1444] has been carried out using angle-resolved photoemission. The line width of the single narrow peak corresponding to a transition from the isolated surface feature of even symmetry has been found to exhibit no changes with temperature in the range from 100 to 700 K. The peak previously reported by Plummer and Eberhardt as a transition from the odd majority surface state has been resolved into majority and minority components at room temperature half-way along the ̅Γ̅M direction. These components have been observed to move towards each other with increasing temperature and are no longer resolvable above 400 K. The width of the single peak for temperatures at and above the Curie temperature (T_c) suggests, however, a non-vanishing exchange splitting above T_c, indicative of short-range magnetic order.