Limits on the anisotropy of the superconducting energy gap of gallium in the A-B plane using normal superconductor tunneling

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1978

OSTI ID:6132860

Kalvey, V R

Superconducting energy gap anisotropy in Gallium is investigated using N-S tunneling with emphasis on reproducibility of data. Gallium crystals at 4 different orientations in the A-B plane were grown in a clean and temperature/humidity controlled environment. Tunnel junctions were formed by evaporating 2000 A silver film on Gallium crystals after natural barrier growth. I-V curves on 18 high quality junctions were collected in a He/sup 3/-He/sup 4/ dilution refrigerator, inside a screened room, at T approx. = 0.14K. The energy gap was obtained by fitting the theoretical I-V curves (based on BCS density of states) to the experimental curves using the energy gap as a fitting parameter. Reproducibility of data was found to be within 1%. Gap anisotropy in Gallium is estimated to lie between 7.3% and 4.2%, in basic agreement with earlier works. The N-S tunneling technique was found superior to S-S' technique for obtaining the gaps using the curve fitting procedure.

• Research Organization: Georgetown Univ., Washington, DC (USA)
• OSTI ID: 6132860
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104* -- Metals & Alloys-- Physical Properties
656102 -- Solid State Physics-- Superconductivity-- Acoustic
Electronic
Magnetic
Optical
& Thermal Phenomena-- (-1987)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANISOTROPY
DATA
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELEMENTS
ENERGY GAP
EXPERIMENTAL DATA
GALLIUM
INFORMATION
METALS
NUMERICAL DATA
PHYSICAL PROPERTIES
SILVER
SUPERCONDUCTIVITY
SUPERCONDUCTORS
TRANSITION ELEMENTS
TUNNEL EFFECT