Upper critical fields and superconducting transition temperatures of some zirconium-base amorphous transition-metal alloys

Journal Article · Mon Aug 01 00:00:00 EDT 1983 · Phys. Rev. B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.28.1396· OSTI ID:5655635

Karkut, M G; Hake, R R

Superconducting upper critical fields H/sub c/2(T), transition temperatures T/sub c/, and normal-state electrical resistivities rho/sub n/ have been measured in the amorphous transition-metal alloy series Zr/sub 1-z/Co/sub x/, Zr/sub 1-x/Ni/sub x/, (Zr/sub 1-x/Ti/sub x/)/sub 0.78/Ni/sub 0.22/, and (Zr/sub 1-x/Nb/sub x/)/sub 0.78/Ni/sub 0.22/. Structural integrity of these melt-spun alloys is indicated by x-ray, density, bend-ductility, normal-state electrical resistivity, superconducting transition width, and mixed-state flux-pinning measurements. The specimens display T/sub c/ = 2.1--3.8 K, rho/sub n/ = 159--190 ..mu cap omega.. cm, and Vertical Bar(dH/sub c/2/dT)cVertical Bar = 28--36 kG/K. These imply electron mean free paths lroughly-equal2--6 A, zero-temperature Ginzburg-Landau coherence distances xi/sub G/0roughly-equal50--70 A, penetration depths lambda/sub G/0roughly-equal(7--10) x 10/sup 3/ A, and extremely high dirtiness parameters xi/sub 0//lroughly-equal300--1300. All alloys display H/sub c/2(T) curves with negative curvature and (with two exceptions) fair agreement with the standard dirty-limit theory of Werthamer, Helfand, Hohenberg, and Maki (WHHM) for physically reasonable values of spin-orbit-coupling induced, electron-spin-flip scattering time tau/sub so/. This is in contrast to the anomalously elevated H/sub c/2(T) behavior which is nearly linear in T that is observed by some, and the unphysically low-tau/sub so/ fits to WHHM theory obtained by others, for various amorphous alloys.

• Research Organization: Department of Physics, Indiana University, Bloomington, Indiana 47405
• OSTI ID: 5655635
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Journal Name: Phys. Rev. B: Condens. Matter; (United States) Vol. 28:3; ISSN PRBMD
• 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
ALLOYS
COBALT ALLOYS
CRITICAL FIELD
DATA
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
EXPERIMENTAL DATA
INFORMATION
MAGNETIC FIELDS
NICKEL ALLOYS
NIOBIUM ALLOYS
NUMERICAL DATA
PHYSICAL PROPERTIES
REACTIVITY COEFFICIENTS
SUPERCONDUCTIVITY
TEMPERATURE COEFFICIENT
TEMPERATURE DEPENDENCE
THERMODYNAMIC PROPERTIES
TITANIUM ALLOYS
TRANSITION TEMPERATURE
ZIRCONIUM ALLOYS
ZIRCONIUM BASE ALLOYS