Photoemission study of single-crystal Bi[sub 2]Sr[sub 1. 9]Pr[sub 0. 1]CuO[sub 6+[delta]]

We performed exploratory angle-integrated and angle-resolved photoemission-spectroscopy measurements on Pr-stabilized single crystals of Bi[sub 2]Sr[sub 2]CuO[sub 6] ([ital T][sub [ital c]][similar to]10 K). Fermi-level crossings along principal directions match some crossings predicted by tight-binding calculations. These crossings differ from both the Fermi-surface mapping and the local-density-approximation-derived Fermi surfaces on the much studied Bi[sub 2]Sr[sub 2]Ca[sub 1]Cu[sub 2]O[sub 8+[delta]] ([ital T][sub [ital c]][similar to]75--96 K). We observe optical-polarization effects in the angle-resolved spectra, which is consistent with the states near [ital E][sub [ital F]] being derived from the orbitals containing [ital d][sub [ital x]][sup 2][minus][ital y][sup 2] symmetry. The density-of-states contribution from the Pr 4[ital f] states derived by resonant-photoemission spectroscopy suggests that the Pr 4[ital f] states do not hybridize strongly and lie away from the Fermi level, thus not affecting the superconductivity of the Bi-Sr-Ca-Cu-O system.