Static and dynamic spin correlations in pure and doped La/sub 2/CuO/sub 4/

Journal Article · Sun May 01 00:00:00 EDT 1988 · Phys. Rev. B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.37.7443· OSTI ID:5221039

Endoh, Y; Yamada, K; Birgeneau, R J; Gabbe, D R; Jenssen, H P; Kastner, M A; Peters, C J; Picone, P J; Thurston, T R; Tranquada, J M; others, and

We report elastic, quasielastic (..integral.. dE), and inelastic neutron-scattering studies of the instantaneous and dynamic spin fluctuations in as-grown and doped La/sub 2/CuO/sub 4/. Four samples have been studied: (A) as-grown La/sub 2/CuO/sub 4/ with T/sub N/ = 195 K, (B) oxygenated La/sub 2/CuO/sub 4/ with T/sub N/approx. =100 K, (C) La/sub 2/Cu/sub 0.95/Li/sub 0.05/O/sub 4/, and (D) La/sub 1.97/Sr/sub 0.03/Cu/sub 0.95/Li/sub 0.05/O/sub 4/. All crystals exhibit variable-range-hopping conductivity behavior. At room temperature each sample exhibits two-dimensional (2D) antiferromagnetic instantaneous correlations in the CuO/sub 2/ sheets with correlation length varying from approx.200 A in crystal A to approx.14 A in crystal D. The integrated intensity and therefore the effective moment is, however, constant to within the experimental error. In samples A and B the 2D correlation length becomes sufficiently large with decreasing temperature that the interplanar coupling is able to drive a transition to 3D long-range order. The spin dynamics have been studied in detail in crystals A and B and quite unusual behavior is observed. In contrast to previously studied planar antiferromagnets, there is no significant Eapprox. =0 component for temperatures greater than or equal toT/sub N/ and instead the 2D response function is highly inelastic. The effective dispersion of the spin excitations is greater than or equal to0.4 eV A. This large energy scale for the spin fluctuations gives credence to models of the superconductivity in doped La/sub 2/CuO/sub 4/ in which the pairing is magnetic in origin

• Research Organization: Department of Physics, Tohoku Universtiy, Sendai 980, Japan
• OSTI ID: 5221039
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Vol. 37:13
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
LANTHANUM COMPOUNDS
ANTIFERROMAGNETISM
CRYSTAL STRUCTURE
SPIN
SUPERCONDUCTIVITY
CUPRATES
DOPED MATERIALS
LITHIUM ADDITIONS
NEEL TEMPERATURE
NEUTRON DIFFRACTION
STRONTIUM ADDITIONS
ALLOYS
ANGULAR MOMENTUM
COHERENT SCATTERING
COPPER COMPOUNDS
DIFFRACTION
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
LITHIUM ALLOYS
MAGNETISM
MATERIALS
OXYGEN COMPOUNDS
PARTICLE PROPERTIES
PHYSICAL PROPERTIES
RARE EARTH COMPOUNDS
SCATTERING
STRONTIUM ALLOYS
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
TRANSITION TEMPERATURE
360204* - Ceramics
Cermets
& Refractories- Physical Properties
656100 - Condensed Matter Physics- Superconductivity