Superconductivity at 40 K in the oxygen-defect perovskites La/sub 2-x/Sr/sub x/CuO/sub 4-y/

Journal Article · Fri Mar 13 04:00:00 EST 1987 · Science (Washington, D.C.); (United States)

DOI:https://doi.org/10.1126/science.235.4794.1373· OSTI ID:6228707

Tarascon, J M; Greene, L H; McKinnon, W R; Hull, G W; Geballe, T H

Structural, magnetic, and electronic properties of compounds in the series La/sub 2-x/Sr/sub x/CuO/sub 4-y/ for 0.05 less than or equal to x less than or equal to 1.1, with ..delta..x = 0.025, were studied. Resistance, susceptibility, Meissner, and shielding measurements have revealed superconductivity among several members of the series. For x = 0.15, the transition temperature T/sub c/, measured at the midpoint of the resistive transition, is a maximum at 39.3 K with a width of 2K. At other compositions the transition is broader and occurs at a lower temperature. Annealing the x = 0.15 sample in oxygen at 500/sup 0/C increases Tsub c/ to 40.3 K., while annealing at the same temperature under vacuum suppresses the superconductivity. These changes in oxygen content and T/sub c/ are reversible. 20 references, 6 figures, 1 table.

• Research Organization: Bell Communications Research, Red Bank, NJ
• OSTI ID: 6228707
• Journal Information: Science (Washington, D.C.); (United States), Journal Name: Science (Washington, D.C.); (United States) Vol. 235; ISSN SCIEA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
ALKALINE EARTH METAL COMPOUNDS
ANNEALING
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
CRYSTAL STRUCTURE
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
HEAT TREATMENTS
LANTHANUM COMPOUNDS
LANTHANUM OXIDES
OXIDES
OXYGEN COMPOUNDS
PEROVSKITES
PHYSICAL PROPERTIES
RARE EARTH COMPOUNDS
STRONTIUM COMPOUNDS
STRONTIUM OXIDES
SUPERCONDUCTIVITY
TRANSITION ELEMENT COMPOUNDS
VERY LOW TEMPERATURE