Electron tunneling into Nb/sub 3/Sn, Nb/sub 3/Ge, and Nb/sub 3/Al

Journal Article · Sat Feb 01 04:00:00 EST 1986 · Phys. Rev. B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.33.1621· OSTI ID:6306384

Geerk, J; Kaufmann, U; Bangert, W; Rietschel, H

We have prepared high-quality tunnel junctions on thin films of Nb/sub 3/Sn, Nb/sub 3/Ge, and Nb/sub 3/Al with artificial tunnel barriers of Al oxide and AlZr oxide. The Nb/sub 3/Sn/AlZr-oxide/Pb tunnel junctions prepared on Sn-deficient material showed no measurable proximity effect. Whereas the tunnel spectra of Sn-deficient A15 NbSn could be satisfactorily analyzed by the standard Rowell-McMillan inversion procedure, the reduced density of states of the stoichiometric samples exhibited characteristic deformations in the form of an overswing at energies far above the highest phonon energy. These deformations can be fitted by proximity analysis, but it is shown that they can also be referred to the influence of an electronic density of states which is strongly structured in the range of phonon energies near the Fermi level. A very similar behavior is found for Nb/sub 3/Ge and to a smaller extent for Nb/sub 3/Al.

• Research Organization: Kernforschungszentrum Karlsruhe, Institut fuer Nukleare Festkoerperphysik, P.O.B. 3640, D-7500 Karlsruhe, Federal Republic of Germany
• OSTI ID: 6306384
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Journal Name: Phys. Rev. B: Condens. Matter; (United States) Vol. 33:3; ISSN PRBMD
• Country of Publication: United States
• Language: English

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71 CLASSICAL AND QUANTUM MECHANICS
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75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALLOYS
ALUMINIUM ALLOYS
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
BETA-W LATTICES
CHALCOGENIDES
CRYSTAL LATTICES
CRYSTAL STRUCTURE
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EXPERIMENTAL DATA
FERMI LEVEL
FILMS
GERMANIUM ALLOYS
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NIOBIUM ALLOYS
NUMERICAL DATA
OXIDES
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PROXIMITY EFFECT
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