Superconducting properties of layered Nb/sub 0. 53/Ti/sub 0. 47//Ge structures prepared by dc sputtering

Journal Article · Mon Apr 01 04:00:00 EST 1985 · J. Appl. Phys.; (United States)

DOI:https://doi.org/10.1063/1.335443· OSTI ID:6106020

Jin, B Y; Shen, Y H; Yang, H Q; Wong, H K; Hilliard, J E; Ketterson, J B; Schuller, I K

Sandwich and superlattice structures composed of the high critical field superconducting alloy Nb/sub 0.53/Ti/sub 0.47/ (where the compositions refer to weight percent) and amorphous Ge were sputter-deposited on sapphire substrates using a novel multi-sputter-gun system. The thicknesses of both the superconducting Nb/sub 0.53/Ti/sub 0.47/ and the insulating Ge layers were varied over a wide range in order to study the two-dimensional (2D) and three-dimensional (3D) superconducting properties of these structures. The observed suppression of the measured resistive superconducting transition temperature T/sub c/ with increasing sheet resistance is tentatively interpreted using the Maekawa--Fukuyama theory which incorporates contributions from localization and Coulomb interaction effects. The upper critical fields, with the field both normal H/sub c/2perpendicular and parallel H/sub c/2parallel to the film, were measured up to 50 kG. H/sub c/2parallel exhibited 2D behavior when the thickness of the superconducting layer was less than 200 A. The zero temperature values of H/sub c/2parallel(0) were estimated using the Rickayzen formula, which is valid in the regime l<<(lxi/sub 0/)/sup 1//sup ///sup 2/<

• Research Organization: Materials Research Center, Northwestern University, Evanston, Illinois 60201
• OSTI ID: 6106020
• Journal Information: J. Appl. Phys.; (United States), Journal Name: J. Appl. Phys.; (United States) Vol. 57:7; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360101 -- Metals &amp; Alloys-- Preparation &amp; Fabrication
360104* -- Metals &amp; Alloys-- Physical Properties
ALLOYS
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CHALCOGENIDES
COATINGS
CORUNDUM
CRITICAL FIELD
DEPOSITION
DIMENSIONS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELEMENTS
FABRICATION
FILMS
GERMANIUM
HETEROJUNCTIONS
JUNCTIONS
LAYERS
MAGNETIC FIELDS
METALS
MINERALS
NIOBIUM ALLOYS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
SAPPHIRE
SEMICONDUCTOR JUNCTIONS
SPUTTERING
SUPERCONDUCTING FILMS
SUPERCONDUCTING JUNCTIONS
SUPERCONDUCTIVITY
SUPERLATTICES
SURFACE COATING
THICKNESS
TITANIUM ALLOYS
VAPOR DEPOSITED COATINGS