Structural characterization of La/sub 2-//sub x/M/sub x/CuO/sub 4/ (M = Sr,Ba) samples by synchrotron x-ray and neutron powder diffraction techniques

Journal Article · Tue Nov 01 04:00:00 EST 1988 · J. Mat. Res.; (United States)

OSTI ID:7016182

Cox, D E; Moss, S C; Meng, R L; Hor, P H; Chu, C W

High-resolution synchrotron x-ray powder diffraction studies on samples of La/sub 2-//sub x/M/sub x/CuO/sub 4/ (M = Sr,Ba) prepared by standard ceramic techniques show that macroscopic compositional inhomogeneities may exist that are unlikely to be revealed by conventional x-ray diffraction methods. Rietveld refinement of neutron data collected at 200, 50, and 11 K from one such sample, nominally La/sub 1.8/Sr/sub 0.2/CuO/sub 4/, gave satisfactory fits to a tetragonal structure of K/sub 2/NiF/sub 4/ type at all three temperatures. However, careful individual peak fits revealed that part of the sample transforms to orthorhombic between 200 and 50 K. It is suggested that this multiphase character has an important influence on the superconducting properties.

• Research Organization: Department of Physics, Brookhaven National Laboratory, Upton, New York 11973
• OSTI ID: 7016182
• Journal Information: J. Mat. Res.; (United States), Journal Name: J. Mat. Res.; (United States) Vol. 3:6; ISSN JMREE
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202* -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
BARIUM OXIDES
BREMSSTRAHLUNG
CHALCOGENIDES
CHEMICAL COMPOSITION
COHERENT SCATTERING
COPPER COMPOUNDS
COPPER OXIDES
CRYSTAL STRUCTURE
DIFFRACTION
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTROMAGNETIC RADIATION
LANTHANUM COMPOUNDS
LANTHANUM OXIDES
NEUTRON DIFFRACTION
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
RADIATIONS
RARE EARTH COMPOUNDS
SAMPLE PREPARATION
SCATTERING
STRONTIUM COMPOUNDS
STRONTIUM OXIDES
SUPERCONDUCTIVITY
SYNCHROTRON RADIATION
TRANSITION ELEMENT COMPOUNDS
X-RAY DIFFRACTION