Tunneling spectroscopy of the superconducting energy gap in {ital R}Ni{sub 2}B{sub 2}C ({ital R}=Y and Lu)

Journal Article · Fri Mar 01 04:00:00 EST 1996 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.53.5640· OSTI ID:279090

Ekino, T; Fujii, H ^[1]; Kosugi, M; Zenitani, Y; Akimitsu, J ^[2]

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1. Faculty of Integrated Arts and Sciences, Hiroshima University, Higashi-Hiroshima 739 (Japan)
2. Department of Physics, Aoyama-Gakuin University, Setagaya, Tokyo 157 (Japan)

Superconducting energy gap in {ital R}Ni{sub 2}B{sub 2}C ({ital R}=Y and Lu) has been investigated using a break-junction tunneling technique. The observed differential conductance {ital dI}/{ital dV} is well described by the BCS density of states with a small lifetime broadening parameter. We have found small gap values for the local low-{ital T}{sub {ital c}} phases in addition to the bulk {ital T}{sub {ital c}} of 15.6{endash}16.6 K. The gap value of 2{Delta}=4.5 meV with {ital T}{sub {ital c}}=15 K gives the BCS ratio of 2{Delta}/{ital k}{sub {ital BT}}{sub {ital c}}=3.5, which is kept constant down to the observed lowest {ital T}{sub {ital c}} of 4.6 K. These results give clear evidence for the BCS mechanism of superconductivity for these compounds. {copyright} {ital 1996 The American Physical Society.}

• OSTI ID: 279090
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 9 Vol. 53; ISSN 0163-1829; ISSN PRBMDO
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
BCS THEORY
BORON CARBIDES
ENERGY GAP
ENERGY-LEVEL DENSITY
LUTETIUM CARBIDES
NICKEL CARBIDES
SUPERCONDUCTORS
TRANSITION TEMPERATURE
TUNNEL EFFECT
YTTRIUM CARBIDES