Point-contact tunneling study of the high-transition-temperature-superconductor Bi sub 2 Sr sub 2 CaCu sub 2 O sub 8

Miscellaneous · Tue Jan 01 00:00:00 EST 1991

OSTI ID:7110709

Jiang, M H

The point-contact (Pt-Ir probe) tunneling measurements on high-T{degree}c superconducting Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8} single crystals ({Tc} = 82 K) have been performed at low temperatures of 4.2 K to 77 K. A high-conductance region around the origin, which is attributed to the junction of the pure-metallic-bridge type of point-contact tunneling, was observed. There are also several current steps beyond the high-conductance region in the I-V curves, corresponding to conductance troughs, which are either zero or negative, in the dI/dV characteristics in the tunneling spectra. These are pronounced structures indicative of bound states in tunneling spectroscopy. a superconducting energy gap of {Delta} = 28 {plus minus} 2 meV was identified from tunneling spectra taken at 4.2 K and as a function of temperature. Current jumps and drops with some regularity in voltage intervals between jumps occur at high applied voltage (> 100 mV). This resonance tunneling is the result of the effects of quantization due to the layered-structure of the crystal. A model based on the superlattice-like nature of the crystal was developed to interpret the tunneling observation of the bound states and the energy gap.

• Research Organization: Drexel Univ., Philadelphia, PA (United States)
• OSTI ID: 7110709
• Resource Relation: Other Information: Thesis (Ph.D.)
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BISMUTH OXIDES
TUNNEL EFFECT
CALCIUM OXIDES
COPPER OXIDES
HIGH-TC SUPERCONDUCTORS
STRONTIUM OXIDES
ENERGY GAP
MONOCRYSTALS
TRANSITION TEMPERATURE
ALKALINE EARTH METAL COMPOUNDS
BISMUTH COMPOUNDS
CALCIUM COMPOUNDS
CHALCOGENIDES
COPPER COMPOUNDS
CRYSTALS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
STRONTIUM COMPOUNDS
SUPERCONDUCTORS
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
360207* - Ceramics
Cermets
& Refractories- Superconducting Properties- (1992-)