American Physical Society, Physical review B, 7(77)
DOI: 10.1103/physrevb.77.075415
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By means of angle-resolved photoemission, we have uncovered surface related states on the pristine and hydrogen saturated Ni(111) surfaces. Near normal emission spectra were recorded at room temperature as a function of photon energy. A hidden Tamm surface state is found on the clean Ni(111) surface at a binding energy of ˜1.19eV , completely masked by the Lambda1 bulk d band. The existence of this surface state is in agreement with the density-functional theory calculations presented here. On the other hand, a surface state related to hydrogen adsorbed on the surface has been identified at a binding energy of ˜0.22eV . Under hydrogen exposure, it grows at the same rate as the three other surface states of the clean Ni(111) vanish.