SUPERCONDUCTIVE PROPERTIES OF THIN TIN FILMS

Technical Report · Tue Nov 01 04:00:00 EST 1960

OSTI ID:4114048

Crittenden, Jr, E C; Cooper, J N; Schmidlin, F W

The superconductive properties of a carefully prepared family of eight thin tin films with thicknesses varying from 0.03 to 1.04 mu were studied in the temperature range between 1.3 and 3.9 deg K. The films were prepared by vacuum evaporation upon polished glass substrates cooled to -20 deg C. Film thicknesses were measured by Fabry-Perot interferometry and were also calculated both from mass evaporated and from resistance measurements. Critical temperatures, particularly for the thinner films, were peratures, particularly for the thinner films, were substantially above that for bulk tin, presumably because of tensile stresses. The d-c critical currents as a function of thickness t can be well approximated by an expression of the form A(1 -- e/sup -t//a)/sup sigma // (+ e / sup -t///sup ss>s/sup s/), where A-bar is a constant determined by the temperature and sigma is about 0.16 mu , essentially independent of temperature. (auth)

• Research Organization: Space Technology Labs., Inc. Physical Research Lab., Los Angeles
• NSA Number: NSA-15-007883
• OSTI ID: 4114048
• Report Number(s): NP-9763; STL/TR-60-0000-NR356
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

CLEANING
COOLING
CURRENTS
ELECTRIC CONDUCTIVITY
EQUATIONS
EVAPORATION
FILMS
GLASS
LOW TEMPERATURE
MASS
MEASURED VALUES
OPTICAL SYSTEMS
PHYSICS
STRESSES
SUPERCONDUCTIVITY
TENSILE PROPERTIES
THICKNESS
TIN
VACUUM