Comparison of paramagnetic- and nonmagnetic-impurity effects on superconductivity in Nd sub 1. 85 Ce sub 0. 15 CuO sub 4

Journal Article · Wed May 01 00:00:00 EDT 1991 · Physical Review, B: Condensed Matter; (USA)

DOI:https://doi.org/10.1103/PhysRevB.43.10489· OSTI ID:5692206

Sugiyama, J; Tokuono, S; Koriyama, S; Yamauchi, H; Tanaka, S ^[1]

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1. Superconductivity Research Laboratory, International Superconductivity Technology Center, 10-13 Shinonome 1-chome, Koto-ku, Tokyo 135, Japan (JP)

The effects of substitution of Co, Ni, or Zn for Cu in the electron-doped superconductors, Nd{sub 1.85}Ce{sub 0.15}Cu{sub 1{minus}{ital x}M{ital x}}O{sub 4} (with {ital M}=Co, Ni, or Zn, {ital x}{le}0.05), have been investigated by powder x-ray diffraction analysis and resistivity, magnetic-susceptibility, and Hall-coefficient measurements. It is observed that only 0.7% Co or 0.8% Ni substitution for Cu destroys superconductivity. On the contrary, for the Zn-substituted samples, it is observed that {ital T}{sub {ital c}} decreases proportionally to {ital x} and the magnitude of {ital T}{sub {ital c}} is {similar to}9 K even for the 2% Zn-substituted sample. This result suggests that the pair-breaking effect plays a dominant role in the suppression of superconductivity in the Co- or Ni-substitute samples. The absolute values of the exchange-interaction energy between an electron and a Co ion and of that between an electron and a Ni ion are estimated at {similar to}0.09 and {similar to}0.08 eV, respectively. These values are comparable to those of the conventional BCS-type superconductors containing paramagnetic impurities. Both the absolute value of the Hall coefficient ({vert bar}{ital R}{sub {ital H}}{vert bar}) and its temperature coefficient ({ital d}{vert bar}{ital R}{sub {ital H}}{vert bar}/{ital dT}) are found to decrease as {ital x} increases for all the samples at temperatures higher than 120 K. However, for the Co-substituted samples, it is clearly observed that {vert bar}{ital R}{sub {ital H}}{vert bar} increases proportionally to {ital x} at 30 K, while {vert bar}{ital R}{sub {ital H}}{vert bar} decreases monotonically with increasing {ital x} for the Ni- or Zn-substitute samples. Therefore, it seems that there are no clear relations between the temperature dependence of {ital R}{sub {ital H}} and the suppression in the magnitude of {ital T}{sub {ital c}} due to the substitutional effects.

• OSTI ID: 5692206
• Journal Information: Physical Review, B: Condensed Matter; (USA), Journal Name: Physical Review, B: Condensed Matter; (USA) Vol. 43:13; ISSN 0163-1829; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
ALLOYS
CERIUM COMPOUNDS
CERIUM OXIDES
CHALCOGENIDES
COBALT ADDITIONS
COBALT ALLOYS
COHERENT SCATTERING
COPPER COMPOUNDS
COPPER OXIDES
DIFFRACTION
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
EXCHANGE INTERACTIONS
HALL EFFECT
INTERACTIONS
MAGNETIC PROPERTIES
MAGNETIC SUSCEPTIBILITY
NEODYMIUM COMPOUNDS
NEODYMIUM OXIDES
NICKEL ADDITIONS
NICKEL ALLOYS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
QUANTITY RATIO
RARE EARTH COMPOUNDS
SCATTERING
SUPERCONDUCTIVITY
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
TRANSITION TEMPERATURE
X-RAY DIFFRACTION
ZINC ADDITIONS
ZINC ALLOYS