Optical phonons in YBa sub 2 Cu sub 4 O sub 8 and Y sub 2 Ba sub 4 Cu sub 7 O sub 15 minus. delta

Journal Article · Fri Jun 01 04:00:00 EDT 1990 · Physical Review, B: Condensed Matter; (USA)

DOI:https://doi.org/10.1103/PhysRevB.41.11058· OSTI ID:6815595

Heyen, E T; Liu, R; Thomsen, C; Kremer, R; Cardona, M ^[1]; Karpinski, J; Kaldis, E; Rusiecki, S ^[2]

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1. Max-Planck-Institut fuer Festkoerperforschung, Heisenbergstrasse 1, D-7000 Stuttgart 80, Federal Republic of Germany (DE)
2. Laboratorium fuer Festkoerperphysik, Eidgenoessische Technische Hochschule, 8093 Zuerich, (Switzerland)

We present Raman spectra of high-temperature superconducting single crystals of YBa{sub 2}Cu{sub 4}O{sub 8} and Y{sub 2}Ba{sub 4}Cu{sub 7}O{sub 15{minus}{delta}}, differing from the well-known YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} by having double CuO chains. By performing polarization-dependent measurements, we were able to identify the symmetry of the observed phonons. In both materials, we detected four out of six Raman-allowed modes of the double Cu(1)-O(1) chains and assign the peaks to Cu(1) {ital A}{sub {ital g}} (250 cm{sup {minus}1}), O(1) {ital A}{sub {ital g}} (605 cm{sup {minus}1}), Cu(1) {ital B}{sub 3{ital g}} (314 cm{sup {minus}1}), and O(1) {ital B}{sub 2{ital g}} (228 cm{sup {minus}1}) in addition to the 5 {ital A}{sub {ital g}} phonons (in YBa{sub 2}Cu{sub 4}O{sub 8} near 104, 153, 341, 438, and 500 cm{sup {minus}1}), which are also present in the well-known YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}}. Contrary to previous reports of Raman scattering on double-CuO{sub 2}-plane superconductors, {ital B}{sub 2{ital g}} and {ital B}{sub 3{ital g}} phonons can unambiguously be observed.

• OSTI ID: 6815595
• Journal Information: Physical Review, B: Condensed Matter; (USA), Journal Name: Physical Review, B: Condensed Matter; (USA) Vol. 41:16; ISSN PRBMD; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
ALKALINE EARTH METAL COMPOUNDS
ASYMMETRY
BARIUM COMPOUNDS
BARIUM OXIDES
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
CRYSTALS
MONOCRYSTALS
OXIDES
OXYGEN COMPOUNDS
PHONONS
POLARIZATION
QUASI PARTICLES
RAMAN SPECTRA
SPECTRA
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
YTTRIUM OXIDES