Antiferromagnetism in the high-T/sub c/-related compounds. [La)sub 2)CuO)sub 4-y); yBa)sub 2)Cu)sub 3)O)sub 6-y)]

Conference · Thu Jan 01 04:00:00 EST 1987

OSTI ID:5255600

Sinha, S K; Moncton, D E; Johnston, D C; Vaknin, D; Shirane, G; Stassis, C

Magnetic susceptibility measurements on La/sub 2/CuO/sub 4-y/ have revealed maxima in temperature indicative of antiferromagnetic ordering. Powder diffraction measurements have demonstrated the existence of superlattice peaks at temperatures below those corresponding to the susceptibility maxima, and polarized neutron measurements have confirmed that the peaks are indeed of magnetic origin. The deduced antiferromagnetic structure in the orthorhombic (Cmca) phase of La/sub 2/CuO/sub 4-y/ consists of ferromagnetic sheets of Cu atoms in the b-c plane which are alternating in sign along the a-axis (100). The moment is parallel to the c-axis. The Neel temperature is extremely sensitive to the oxygen deficiency y and decreases rapidly t zero as y goes from 0.03 to zero. The saturated moment is approx. =0.4 ..mu../sub B/Cu atom for samples with the highest T/sub N/ (290 K). Antiferromagnetic spin fluctuations have also been observed by polarized neutron scattering in the paramagnetic phase above T/sub N/. Recent results obtained on magnetic ordering in the YBa/sub 2/Cu/sub 3/O/sub 6-y/ family of compounds are also discussed, together with the possible implications for novel superconductivity mechanisms. 23 refs., 5 figs

• Research Organization: Exxon Research and Engineering Co., Annandale, NJ (USA); Brookhaven National Lab., Upton, NY (USA); Ames Lab., IA (USA)
• DOE Contract Number: AC02-76CH00016
• OSTI ID: 5255600
• Report Number(s): BNL-40828; CONF-871126-12; ON: DE88007571
• 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
ANTIFERROMAGNETISM
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
LANTHANUM COMPOUNDS
LANTHANUM OXIDES
MAGNETIC MOMENTS
MAGNETIC PROPERTIES
MAGNETIC SUSCEPTIBILITY
MAGNETISM
NEEL TEMPERATURE
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
RARE EARTH COMPOUNDS
SUPERCONDUCTIVITY
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
TRANSITION TEMPERATURE