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Author Yoshida, M. ♦ Tajima, S. ♦ Mizuo, Y. ♦ Wada, T. ♦ Ichinose, A. ♦ Yaegashi, Y. ♦ Koshizuka, N. ♦ Yamauchi, H. ♦ Tanaka, S.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword MATERIALS SCIENCE ♦ CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY ♦ BARIUM OXIDES ♦ RAMAN SPECTROSCOPY ♦ CERIUM OXIDES ♦ COPPER OXIDES ♦ ERBIUM OXIDES ♦ EUROPIUM OXIDES ♦ HIGH-TC SUPERCONDUCTORS ♦ LANTHANUM OXIDES ♦ CRYSTAL STRUCTURE ♦ PHONONS ♦ TRANSITION TEMPERATURE ♦ ALKALINE EARTH METAL COMPOUNDS ♦ BARIUM COMPOUNDS ♦ CERIUM COMPOUNDS ♦ CHALCOGENIDES ♦ COPPER COMPOUNDS ♦ ERBIUM COMPOUNDS ♦ EUROPIUM COMPOUNDS ♦ LANTHANUM COMPOUNDS ♦ LASER SPECTROSCOPY ♦ OXIDES ♦ OXYGEN COMPOUNDS ♦ PHYSICAL PROPERTIES ♦ QUASI PARTICLES ♦ RARE EARTH COMPOUNDS ♦ SPECTROSCOPY ♦ SUPERCONDUCTORS ♦ THERMODYNAMIC PROPERTIES ♦ TRANSITION ELEMENT COMPOUNDS ♦ Ceramics, Cermets, & Refractories- Physical Properties ♦ Condensed Matter Physics- Superconductivity
Abstract Raman-scattering spectra of (Eu{sub 2/3}Ce{sub 1/3}){sub 2}(Ba{sub 2/3}Eu{sub 1/3}){sub 2}Cu{sub 3}O{sub 9} and (Er{sub 2/3}Ce{sub 1/3}){sub 2}(Ba{sub 2/3}La{sub 1/3}){sub 2}Cu{sub 3}O{sub 9}, both of which have Cu-O{sub 5} pyramid structure, as well as YBa{sub 2}Cu{sub 3}O{sub 7}, have been observed at room temperature with use of single crystals. A scattering peak with {ital B}{sub 1{ital g}} symmetry has been observed at around 180 cm{sup {minus}1} and peaks with {ital A}{sub 1{ital g}} symmetry at around 220, 290, 450, and 540 cm{sup {minus}1}, in both compounds. The 180-cm{sup {minus}1} peak with {ital B}{sub 1{ital g}} symmetry is assigned to the out-of-phase bending of oxygen in the Cu-O{sub 2} plane and the 540-cm{sup {minus}1} peak with {ital A}{sub 1{ital g}} symmetry to the stretching of apical oxygen. Phonon-energy calculation has been performed with use of ionic potentials obtained for YBa{sub 2}Cu{sub 3}O{sub 7}. To explain the observed {ital B}{sub 1{ital g}} phonon energies, it has been found that the polarizability of the oxygen in the Cu-O{sub 2} plane in these compounds must be increased in relation to that in YBa{sub 2}Cu{sub 3}O{sub 7}. The 220- and 290-cm{sup {minus}1} peaks are tentatively assigned to the mixed vibrational modes of oxygens in the Cu-O{sub 2} plane and lanthanide atoms.
ISSN 01631829
Educational Use Research
Learning Resource Type Article
Publisher Date 1991-07-01
Publisher Place United States
Journal Physical Review, B: Condensed Matter
Volume Number 44
Issue Number 2


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