Antiferromagnetism and mixed valency in YBa/sub 2/Cu/sub 3/O/sub 6+x/

Conference · Fri Jan 01 04:00:00 EST 1988

OSTI ID:7090554

Tranquada, J M

Results of some recent neutron diffraction studies of antiferromagnetic ordering and x-ray absorption studies of Cu valence in YBa/sub 2/Cu/sub 3/O/sub 6+x/ will be reviewed. X-ray absorption measurements at the Cu K-edge demonstrate that when oxygen is removed from a CuO chain, the Cu/sup 2 +/ ions in that chain are converted to Cu/sup 1 +/, thus helping to maximize the number of O 2p holes present in the orthorhombic phase, which in turn keeps the superconducting transition temperature high. Neutron diffraction studies have demonstrated that long-range antiferromagnetic ordering occurs throughout the tetragonal phase, predominantly due to Cu/sup 2 +/ ions in the CuO/sub 2/ planes. The increasing number of Cu/sup 2 +/ ions in chain sites with increasing oxygen content causes frustration in interplanar coupling, and eventually a change in spin structure. The recent growth of very large single crystals has made possible inelastic scattering studies of spin waves. 27 refs., 6 figs.

• Research Organization: Brookhaven National Lab., Upton, NY (USA)
• DOE Contract Number: AC02-76CH00016
• OSTI ID: 7090554
• Report Number(s): BNL-41471; CONF-880914-4; ON: DE88015201
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
656100 -- Condensed Matter Physics-- Superconductivity
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALKALINE EARTH METAL COMPOUNDS
ANTIFERROMAGNETISM
BARIUM COMPOUNDS
BARIUM OXIDES
CHALCOGENIDES
COHERENT SCATTERING
COPPER COMPOUNDS
COPPER OXIDES
DIFFRACTION
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTRONIC STRUCTURE
MAGNETISM
NEUTRON DIFFRACTION
OXIDES
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
SCATTERING
SUPERCONDUCTIVITY
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
TRANSITION TEMPERATURE
VALENCE
YTTRIUM COMPOUNDS
YTTRIUM OXIDES