Superconductivity and magnetism in Eu sub 1 minus x Pr sub x Ba sub 2 Cu sub 3 O sub 7 minus. delta

Journal Article · Tue Oct 01 00:00:00 EDT 1991 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.44.6999· OSTI ID:5160463

Nieva, G; Ghamaty, S; Lee, B W; Maple, M B; Schuller, I K ^[1]

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1. California Univ., San Diego, La Jolla, CA (United States). Dept. of Applied Physics and Information Science California Univ., San Diego, La Jolla, CA (United States). Inst. of Pure and Applied Physical Sciences Department of Physics and Institute for Pure and Applied Physical Sciences University of California, San Diego, La Jolla, California (USA)

Measurements of the electrical resistivity {rho} as a function of temperature {ital T}, and low-temperature specific heat {ital C} as a function of {ital T} and magnetic field {ital H}, have been performed for Pr concentrations 0{le}{ital x}{le}1 in the Eu{sub 1{minus}{ital x}}Pr{sub {ital x}}Ba{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} system ({delta}{approx}0.05). The superconducting critical temperature {ital T}{sub {ital c}}({ital x}) in the metallic phase (0{le}{ital x}{approx lt}{ital x}{sub {ital c}}{approx}0.5) was determined from the resistivity {rho}({ital x},{ital T}), while the Neel temperature {ital T}{sub {ital N}}({ital x}) in the insulating phase ({ital x}{sub {ital c}}{approx lt}{ital x}{le}1) was inferred from specific-heat anomalies due to antiferromagnetic (AFM) ordering of the Pr ions. The effect of chemical'' pressure on {ital T}{sub {ital c}}({ital x}) in the Y{sub 1{minus}{ital x}}Pr{sub {ital x}}Ba{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} system is opposite to that of applied hydrostatic pressure. The Pr contributions to the specific heat in the insulating phase have the form {ital C}({ital T})={ital MT}{sup 3} for {ital T}{lt}{ital T}{sub {ital N}}, characteristic of three-dimensional AFM magnons. In contrast, the Pr contribution to {ital C}({ital T}) in the metallic phase takes the form of a broad anomaly that can be described by a spin-1/2 Kondo model. The entropy associated with the Pr specific-heat anomalies in both the metallic and insulating phases is close to {ital R} ln2, indicative of a doublet ground state for Pr in the crystalline electric field and a Pr valence close to 4+.

• DOE Contract Number: FG03-86ER45230
• OSTI ID: 5160463
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 44:13; ISSN 0163-1829; ISSN PRBMD
• 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
COPPER COMPOUNDS
COPPER OXIDES
CRYSTAL FIELD
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ENERGY LEVELS
EUROPIUM COMPOUNDS
EUROPIUM OXIDES
GROUND STATES
HIGH-TC SUPERCONDUCTORS
KONDO EFFECT
MAGNETIC FIELDS
MAGNETISM
MAGNONS
MINERALS
NEEL TEMPERATURE
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PEROVSKITE
PEROVSKITES
PHYSICAL PROPERTIES
PRASEODYMIUM COMPOUNDS
PRASEODYMIUM OXIDES
QUASI PARTICLES
RARE EARTH COMPOUNDS
SPECIFIC HEAT
STOICHIOMETRY
SUPERCONDUCTORS
TEMPERATURE DEPENDENCE
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
TRANSITION TEMPERATURE
VALENCE