Temperature dependence of the spin-Peierls energy gap and anomalous line shapes in CuGeO{sub 3}

Journal Article · Sat Jun 01 04:00:00 EDT 1996 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.53.R14713· OSTI ID:284713

Martin, M C; Shirane, G ^[1]; Fujii, Y; Nishi, M ^[2]; Fujita, O; Akimitsu, J ^[3]; Hase, M ^[4]; Uchinokura, K ^[5]

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1. Department of Physics, Brookhaven National Laboratory, Upton, New York 11973-5000 (United States)
2. Neutron Scattering Laboratory, Institute for Solid State Physics, University of Tokyo, Shirakata, Tokai, Ibaraki 319-11 (Japan)
3. Department of Physics, Aoyama Gakuin University, Chitosedai, Setagaya-ku, Tokyo 157 (Japan)
4. Institute of Physical and Chemical Research (RIKEN), Wako 351-01 (Japan)
5. Department of Applied Physics, University of Tokyo, Bunkyo-ku, Tokyo 113 (Japan)

Neutron-scattering measurements on a large single crystal of CuGeO{sub 3} have been used to determine the temperature dependence of the spin-Peierls energy gap. While the power-law behavior of the intensity of structural superlattice peaks is well fit by {ital I}({ital T}){proportional_to}({ital T}{sub {ital c}}{minus}{ital T}){sup 2{beta}} with an exponent of {beta}=0.33, the exponent for the temperature dependence of the energy gap is significantly smaller than expected for conventional spin-Peierls materials. Usual scaling relations relate the energy gap to the superlattice reflection intensity as {Delta}({ital T}){proportional_to}{ital I}{sup {ital a}} with {ital a}=1/3; the present results suggest an exponent of {ital a}{approx_equal}1/6 for CuGeO{sub 3}. An additional scattering cross section is observed in constant-{ital q} and constant-{ital E} scans creating a long tail extending to higher energies relating to a proposed scattering continuum. {copyright} {ital 1996 The American Physical Society.}

• Research Organization: Brookhaven National Laboratory
• DOE Contract Number: AC02-76CH00016
• OSTI ID: 284713
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 22 Vol. 53; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COPPER OXIDES
CRITICAL EXPONENTS
ENERGY GAP
GERMANIUM OXIDES
MONOCRYSTALS
NEUTRON DIFFRACTION
PEIERLS INSTABILITY
SCALING
SUPERLATTICES
TEMPERATURE DEPENDENCE