Temperature dependence of the phonon frequencies, linewidths, and Raman-continuum scattering of single-domain Y sub 0. 56 Pr sub 0. 44 Ba sub 2 Cu sub 3 O sub 7

Journal Article · Sun Nov 01 04:00:00 EST 1992 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.46.11958· OSTI ID:6947210

McCarty, K F ^[1]; Liu, J Z; Jia, Y X; Shelton, R N ^[2]; Radousky, H B ^[3]

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1. Sandia National Laboratories, Livermore, California 94551-0969 (United States)
2. Department of Physics, University of California, Davis, California 95616 (United States)
3. Department of Physics, University of California, Davis, California 95616 (United States) Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

We report detailed Raman-scattering measurements from a single-domain crystal of composition Y{sub 0.56}Pr{sub 0.44}Ba{sub 2}Cu{sub 3}O{sub 7} ({ital T}{sub {ital c}}=40 K). Through a polarization analysis, 13 of the 15 Raman-active phonons are unambiguously identified. The frequencies and linewidths of the five {ital A}{sub {ital g}} phonons are studied as a function of temperature. Unlike YBa{sub 2}Cu{sub 3}O{sub 7}, there are no pronounced superconductivity-induced changes in phonon frequency and linewidth. At all temperatures, the {ital B}{sub 1{ital g}}-like phonon at 320 cm{sup {minus}1} is intrinsically much broader than in YBa{sub 2}Cu{sub 3}O{sub 7}. The linewidths of the 440- and 515-cm{sup {minus}1} phonons decrease sharply with cooling, to an extent that cannot be explained by the simplest model of anharmonic decay. We identify Raman-scattering continua for photons polarized both within and perpendicular to the CuO{sub 2} planes. Like YBa{sub 2}Cu{sub 3}O{sub 7}, the CuO{sub 2}-plane continuum interferes strongly with the phonon scattering at 130 cm{sup {minus}1}. Unlike YBa{sub 2}Cu{sub 3}O{sub 7}, the CuO{sub 2}-plane continuum of Y{sub 0.56}Pr{sub 0.44}Ba{sub 2}Co{sup 3}O{sub 7} has a low-frequency tail that disappears upon cooling.

• DOE Contract Number: AC04-76DP00789; W-7405-ENG-48
• OSTI ID: 6947210
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 46:18; ISSN PRBMD; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

665411* -- Basic Superconductivity Studies-- (1992-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
BARIUM OXIDES
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
HIGH-TC SUPERCONDUCTORS
LINE WIDTHS
OXIDES
OXYGEN COMPOUNDS
PHONONS
POLARIZATION
PRASEODYMIUM COMPOUNDS
PRASEODYMIUM OXIDES
QUASI PARTICLES
RAMAN SPECTRA
RARE EARTH COMPOUNDS
SPECTRA
SUPERCONDUCTORS
TEMPERATURE DEPENDENCE
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
YTTRIUM OXIDES