Upper critical field and related properties of superconducting amorphous alloys Zr--Si

Journal Article · Fri Jun 01 04:00:00 EDT 1984 · J. Low Temp. Phys.; (United States)

DOI:https://doi.org/10.1007/BF00681771· OSTI ID:6694765

Toyota, N; Inoue, A; Fukase, T; Masumoto, T

The upper critical field H/sub c/2 has been measured for the superconducting amorphous alloys Zr/sub 100-x/Si/sub x/ with x = 13, 15, and 17 over a wide temperature range down to 50 mK. Measurements for related properties, such as the depinning current density J/sub p/, pinning force density F/sub p/, and flux flow resistivity rho/sub f/, reveal that these systems are well characterized as typically soft and dirty type II superconductors with an extremely low J/sub p/ of 1 A/cm/sup 2/ and F/sub p/ of 1.5 x 10/sup 4/ N/m/sup 3/ at h(equivalentH/H/sub c2/) = 0.5 and t(equivalentT/T/sub c/) = 0.5. The temperature dependence of H/sub c2/ is well fitted by a curve of the Werthamer-Helfand-Hohenberg theory with Maki parameter ..cap alpha.. = 1.7--1.5 and spin-orbit interaction parameter lambda/sub so/ = 1--2.4. These results indicate that the Pauli spin-paramagnetic effect plays an important role in the low-temperature behavior of H/sub c2/ in these low-T/sub c/ and high-H/sub c2/ amorphous superconductors. Corrections of the electron-phonon coupling (lambda/sub ep/ = 0.6) to the Pauli spin-paramagnetic limiting field lead to a reduced importance of the spin-orbit interaction effect, with lambda/sub so/ less than 1.0 A discussion is given of the structural inhomogeneities in an amorphous phase, which are sensitively reflected in the strength of the fluxoid line pinning interaction (J/sub p/, F/sub p/) and are intimately related to the nonintrinsic anomaly, observed in many amorphous alloys, that H/sub c2/ values.

• Research Organization: The Research Institute for Iron, Steel and Other Metals, Tohoku University, Sendai, Japan
• OSTI ID: 6694765
• Journal Information: J. Low Temp. Phys.; (United States), Journal Name: J. Low Temp. Phys.; (United States) Vol. 55:5; ISSN JLTPA
• 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
AMORPHOUS STATE
CRITICAL FIELD
CURRENT DENSITY
DATA
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTRON-PHONON COUPLING
EXPERIMENTAL DATA
INFORMATION
MAGNETIC FIELDS
MAGNETIC FLUX
NUMERICAL DATA
PHYSICAL PROPERTIES
SILICON ALLOYS
SUPERCONDUCTIVITY
TEMPERATURE DEPENDENCE
ULTRALOW TEMPERATURE
ZIRCONIUM ALLOYS
ZIRCONIUM BASE ALLOYS