H. Namatame

Energy scale directly related to superconductivity in high-Tccuprates: Universality from the temperature-dependent angle-resolved photoemission of Bi2Sr2Ca2Cu3O10+δ

S. Ideta, T. Yoshida, A. Fujimori, H. Anzai, T. Fujita, A. Ino, M. Arita, H. Namatame, M. Taniguchi, Z.-X. Shen, K. Takashima, K. Kojima, and S. Uchida Department of Physics, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526, Japan Hiroshima Synchrotron Center, Hiroshima University, Higashi-Hiroshima 739-0046, Japan Department of Applied Physics and Stanford Synchrotron Radiation Laboratory, Stanford University, Stanford, CA94305 (Dated: January 18, 2013)

Electronic structure and metal-insulator transitions in Ti and V oxides

Abstract The electronic structures of various Ti and V oxides have been studied by photoemission and X-ray absorption spectroscopy. For LaxSr1−xTiO3, electron doping induces new photoemission feature within the band gap of SrTiO3. For the 3d1 systems, as the Hubbard gap collapses and U/W becomes small, a new spectral feature grows around the Fermi level.

Electronic structure of the organic conductor (DMe-DCNQI)2Cu studied by photoemission spectroscopy

Abstract An x-ray photoemisson study of (DMe-DCNQI) 2 Cu is reported. The line-shape analysis reveals the mixed valency of Cu + and Cu 2+ , and the Cu 2+ : Cu 2+ ratio is found to be ∼ 2 : 1. This suggest that Cu is in a valance fluctuating state in the metallic state and, in other (DCNQI) 2 Cu compounds, a Cu + ue5f8Cu 2+ charge-ordering takes place below the metal-insulator transition temperature.

ELECTRONIC STRUCTURE OF K0.30MoO3 STUDIED BY ULTRAVIOLET PHOTOEMISSION SPECTROSCOPY

Abstract Ultraviolet photoemission (UPS) spectra of K 0.30 MoO 3 have been obtained using synchrotron radiation from 32 to 100 eV. The conduction and valence bands are observed in the binding energy (E B ) range of 0–2 eV and 2–10 eV. The photoemission intensity of these structures resonantly increases around the photon energy (hυ) of 49 eV, which is much higher than E B of Mo 4p levels. The angle-resolved UPS measurements have been also performed to reveal the band structure of K 0.30 MoO 3 .

Linear and magnetic circular dichroism in the Ce 4d X-ray absorption spectroscopy of CeRh3B2

Abstract We have measured linear and magnetic circular dichroism in the Ce 4d X-ray absorption spectra of CeRh3B2, which has a highly anomalous ferromagnetic state. The result indicates an unusually large axial crystal field of order 0.1–0.2 eV along the hexagonal c-axis.

Photoemission Study of Single Crystal BaPb 1-x Bi x O 3

We have measured photoemission spectra of single crystal BaPb1−xBixO3 at liquid nitrogen temperature. Clear Fermi edges have been observed in the valence band spectra for metallic compositions. The valence band peak dominated by O 2p states does not show a rigid band shift with x. The gross features in the experimental density of states (DOS) agree well with calculated DOS in the insulating phase rather than in the metallic phase.

The electronic structure of BaPb1-xBixO3 studied by photoemission spectroscopy

Abstract We have measured photoemission spectra of BaPb 1−x Bi x O 3 and extracted new information about their electronic structure. O 2p non-bonding states are located around the top of the valence band and possibly form the metallic states at the Fermi level. O 2p-Bi 6s anti-bonding states are located around 1 eV below the Fermi level forming a gap or pseudogap in Bi substituted samples, and their bonding counterpart is located both at around 6 and 10 eV corresponding to the splitting of the anti-bonding states.

Photoemission study of metallic but non-superconducting and insulating copper oxides

Abstract The electronic structure of the metallic but non-superconducting copper oxide La 4 BaCu 5 O 13 and formally Cu 3+ insulator NaCuO 2 is studied by photoemission spectroscopy and cluster model calculations. As for La 4 BaCu 5 O 13 , a Fermi edge has been observed and the valence band and the Cu 2p core level spectra resemble those of Cu-oxide superconductors. From the analysis of the spectra of NaCuO 2 , the charge transfer energy Δ is found to be negative and the band gap is of a p-p type.