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 00:00:00 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), Vol. 45:9; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

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