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

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1982

OSTI ID:7026259

Karkut, M G

A systematic study of H/sub c2/(T) and T/sub c/(x) on the transition-metal amorphous alloy series Zr/sub 1-xNi/sub x/, Zr/sub 1-x/CO/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/ over relatively wide ranges of T and x has been performed. All samples were rapidly quenched from the melt using a melt-spinning device constructed in this laboratory. Our resistively determined H/sub c2/(T) results are consistent with the standard theory (well known to give a reasonable account of H/sub c2/(T) for highly disordered cystalline alloys) in sharp contrast to the anomalously enhanced H/sub c2/(T) curves observed in amorphous alloys by some other investigators. The present work together with recent work in other laboratories now suggests that the latter anomalies are due to alloy inhomogeneities. Our T/sub c/(x) results are consistent with the work of others for the Zr/sub 1-x/Ni/sub x/ and Zr/sub 1-x/Co/sub x/ systems and show that T/sub c/ decreases linearly with x for 21 less than or equal to x less than or equal to 40. For the iso- average valence -electron-to atom ratio) system (Zr/sub 1-x/Ti/sub x/)/sub 0.78Ni/sub 0.22/ (0 less than or equal to x less than or equal to 0.3), T/sub c/ decreases with increasing x, opposite to the behavior of the crystalline hcp Zr/sub 1-x/Ti/sub x/ system. For the (Zr/sub 1-x/Nb/sub x/)0.78 Ni/sub 0.22/ system, T/sub c/ first increases and then decreases with increasing , unlike any other metallic glass alloy system measured to date. The presently observed vagaries in T/sub c/(x) behavior suggest that concomitant measurement of the x dependence of other electronic parameters in the same systems might be particularly valuable in understanding the mechanisms controlling T/sub c/ magnitudes in amorphous alloys.

• Research Organization: Indiana Univ., Bloomington (USA)
• OSTI ID: 7026259
• 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
COBALT ALLOYS
CRITICAL FIELD
DATA
EXPERIMENTAL DATA
INFORMATION
MAGNETIC FIELDS
NICKEL ALLOYS
NIOBIUM ALLOYS
NUMERICAL DATA
PHYSICAL PROPERTIES
QUANTITY RATIO
TEMPERATURE DEPENDENCE
THERMODYNAMIC PROPERTIES
TITANIUM ALLOYS
TRANSITION TEMPERATURE
ZIRCONIUM ALLOYS
ZIRCONIUM BASE ALLOYS