Thermal contraction at the spin-Peierls transition in CuGeO[sub 3]

Journal Article · Tue Nov 01 04:00:00 EST 1994 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.50.12606· OSTI ID:7126877

Harris, Q J; Feng, Q; Birgeneau, R J ^[1]; Hirota, K; Kakurai, K; Lorenzo, J E; Shirane, G ^[2]; Hase, M; Uchinokura, K ^[3]; Kojima, H; Tanaka, I; Shibuya, Y ^[4]

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1. Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)
2. Department of Physics, Brookhaven National Laboratory, Upton, New York 11973 (United States)
3. Department of Applied Physics, The University of Tokyo, Bunkyo-ku, Tokyo 113 (Japan)
4. Institute of Inorganic Synthesis, Yamanashi University, Kofu-shi, Yamanashi 400 (Japan)

We report the results of an x-ray-scattering study of the [ital b]-axis lattice constant of the quasi-one-dimensional spin-1/2 antiferromagnetic chain system CuGeO[sub 3] as a function of temperature and magnetic field. A spontaneous thermal contraction [Delta][ital b] along the [ital b] axis perpendicular to the chain direction is observed below the spin-Peierls transition temperature [ital T][sub [ital c]] near 14 K. The contraction, [Delta][ital b], is well described by a simple power law, [Delta][ital b][proportional to](1[minus][ital T]/[ital T][sub [ital c]])[sup [ital x]], where the exponent [ital x] is found to be close to 0.5. Below the transition temperature, [Delta][ital b] scales with the intensity of the superlattice reflections with indices ([ital h]/2,[ital k],[ital l]/2)([ital h],[ital l]: odd, [ital k]: nonzero integer) measured by neutron scattering. The shift of the transition temperature, [Delta][ital T][sub [ital c]][equivalent to][ital T][sub [ital c]](0)[minus][ital T][sub [ital c]]([ital H]), is found to scale as [ital H][sup 2] in quantitative agreement with the results of magnetic susceptibility measurements and with theory. A small increase in the [ital a]-axis lattice constant is observed below [ital T][sub [ital c]].

• DOE Contract Number: AC02-76CH00016
• OSTI ID: 7126877
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 50:17; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
ALLOY SYSTEMS
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
GERMANIUM COMPOUNDS
GERMANIUM OXIDES
LATTICE PARAMETERS
MAGNETIC FIELDS
MAGNETIC PROPERTIES
MAGNETIC SUSCEPTIBILITY
OXIDES
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
SPECTROSCOPY
TEMPERATURE DEPENDENCE
TERNARY ALLOY SYSTEMS
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
TRANSITION TEMPERATURE
X-RAY SPECTROSCOPY