Superconductivity in amorphous T/sub 5/T/sub 9/ transition metal alloys (T/sub 5/=Nb, Ta; T/sub 9/=Rh, Ir)

Journal Article · Mon Dec 01 04:00:00 EST 1980 · Phys. Rev. B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.22.5213· OSTI ID:6792191

Koch, C C; Kroeger, D M; Scarbrough, J O; Giessen, B C

The superconducting transition temperature T/sub c/ has been measured for amorphous T/sub 5/T/sub 9/ alloys (where T/sub 5/=Nb or Ta, T/sub 9/=Rh or Ir) as a function of composition. Nb and Ta dominated the T/sub c/ behavior with T/sub c/ for Nb alloys approx. =4.8--5.1 K and T/sub c/ for Ta alloys approx. =3.1--3.3 K. Changing the average group number by varying the T/sub 5//T/sub 9/ ratio had little effect on T/sub c/ within the approx.10 at. % range of composition in which the amorphous alloys form. T/sub c/ decreased approximately linearly with x for (Nb/sub 1-x/Ta/sub x/)/sub 55/Rh/sub 45/ and (Nb/sub 1-x/Ta/sub x/)/sub 55/Ir/sub 45/. The electrical resistivity, rho/sub n/ and the upper critical field B/sub c/2 were measured as functions of temperature. The Sommerfeld constant ..gamma.. was calculated from rho/sub n/ and dB/sub c/2/dTVertical BarT/sub c/ using the Ginzburg-Landau-Abrikosov-Gor'kov theory. The Debye temperature THETA/sub D/ was calculated from measurements of Young's modulus. The above parameters allowed calculations to be made of N(E/sub F/), the density of electronic states at the Fermi level, and lambda, the electron-phonon coupling constant. It was found that lambda more accurately reflected the T/sub c/ behavior than did N(E/sub F/) and that both electronic and phonon contributions had to be considered in the determination of lambda.

• Research Organization: Metals and Ceramics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 6792191
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Journal Name: Phys. Rev. B: Condens. Matter; (United States) Vol. 22:11; 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
AMORPHOUS STATE
CRITICAL FIELD
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELEMENTS
IRIDIUM ALLOYS
MAGNETIC FIELDS
METALS
NIOBIUM ALLOYS
PHYSICAL PROPERTIES
PLATINUM METAL ALLOYS
QUANTITY RATIO
RHODIUM ALLOYS
SUPERCONDUCTIVITY
SUPERCONDUCTORS
TANTALUM ALLOYS
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENTS
TRANSITION TEMPERATURE
TYPE-II SUPERCONDUCTORS