Superconductivity under pressure of La sub 2 minus x Ba sub x CuO sub 4 (0. 05 le x le 0. 25) and Nd sub 1. 85 Ce sub 0. 15 CuO sub 4 minus. delta

Journal Article · Sun Mar 01 04:00:00 EST 1992 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.45.4897· OSTI ID:5000708

Liverman, W J ^[1]; Huber, J G ^[2]; Moodenbaugh, A R; Xu, Y ^[3]

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1. Science Museum of Virginia, 2500 W. Broad St., Richmond, Virginia 23220 (United States)
2. 501 N. Boulevard, Richmond, Virginia 23220 (United States)
3. Materials Science Division, Brookhaven National Laboratory, Upton, New York 11973 (United States)

The superconducting transition temperature {ital T} versus pressure {ital p} ({lt}18 kbar) was determined for La{sub 2{minus}{ital x}}Ba{sub {ital x}}CuO{sub 4} ({ital x}=0.05, 0.08, 0.12, 0.125, 0.145, 0.175, and 0.25) and for Nd{sub 1.85}Ce{sub 0.15}CuO{sub 4{minus}{delta}}. The pressure was applied hydrostatically. Transition temperatures were determined using a mutual-inductance technique. For the Ba system, {ital T}{sub {ital c}}'s rise under pressure. The highest {ital dT}{sub {ital c}}/{ital dp} (0.6 K/kbar) was observed for compositions {ital x}=0.12 and 0.125 at which the {ital T}{sub {ital c}} at zero pressure is below 4 K. The results are compared with previous results for Ba and for Sr. Our results for {ital x}=0.12 and 0.125 (broad transitions, an apparently smooth increase in {ital T}{sub {ital c}} with pressure, and {ital T}{sub {ital c}}'s relatively low at all pressures) suggest that samples do not transform to a (higher-{ital T}{sub {ital c}}) crystallographic phase under pressure. The {ital T}{sub {ital c}} for Nd{sub 1.85}Ce{sub 0.15}CuO{sub 4} is found to be essentially pressure independent.

• DOE Contract Number: AC02-76CH00016
• OSTI ID: 5000708
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 45:9; ISSN 0163-1829; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360207* -- Ceramics
Cermets
& Refractories-- Superconducting Properties-- (1992-)
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
BARIUM OXIDES
CERIUM COMPOUNDS
CERIUM OXIDES
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
CRYSTAL-PHASE TRANSFORMATIONS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
HIGH PRESSURE
HIGH-TC SUPERCONDUCTORS
LANTHANUM COMPOUNDS
LANTHANUM OXIDES
MEDIUM PRESSURE
MEDIUM VACUUM
NEODYMIUM COMPOUNDS
NEODYMIUM OXIDES
OXIDES
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
PRESSURE DEPENDENCE
RARE EARTH COMPOUNDS
STOICHIOMETRY
SUPERCONDUCTORS
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE
TEMPERATURE RANGE 0000-0013 K
TEMPERATURE RANGE 0013-0065 K
TEMPERATURE RANGE 0065-0273 K
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
TRANSITION TEMPERATURE
VERY HIGH PRESSURE