PHOTOEMISSION-STUDY OF SINGLE-CRYSTAL BI2SR1.9PR0.1CUO6+DELTA

We performed exploratory angle-integrated and angle-resolved photoemis sion-spectroSCOpY measurements on Pr-stabilized single crystals of Bi2 Sr2CuO6 (T(c) approximately 10 K). Fermi-level crossings along princip al directions match some crossings predicted by tight-binding calculat ions. These crossings differ from both the Fermi-surface mapping and t he local-density-approximation-derived Fermi surfaces on the much stud ied Bi2Sr2Ca1Cu2O8+delta (T(c) approximately 75-96 K). We observe opti cal-polarization effects in the angle-resolved spectra, which is consi stent with the states near E(F) being derived from the orbitals contai ning d(x2-y2) Symmetry. The density-of-states contribution from the Pr 4f states derived by resonant-photoemission spectroscopy suggests tha t the Pr 4f states do not hybridize strongly and lie away from the Fer mi level, thus not affecting the superconductivity of the Bi-Sr-Ca-Cu- O system.