Superconductivity and magnetic order in La-Ce alloys

Thesis/Dissertation · Sat Aug 01 04:00:00 EDT 1970

DOI:https://doi.org/10.2172/4090171· OSTI ID:4090171

Wollan, John Jerome ^[1]

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1. Iowa State Univ., Ames, IA (United States)

Superconductivity and magnetic order have been studied both above and below the Kondo temperature for the La-Ce system. Electrical resistivity measurements on La 0.2, 1.0, 2.0, 3.2, and 4.0 wt. % Ce have been made from 0.06 K to 20 K. All samples showed a Kondo-like minimum, T _min, in the resistivity with a subsequent maximum, T_max. T_min was found to be proportional to n ^1/7, where n is the concentration, and T_max (H = 0) was proportional to n ². The slope of the resistivity due to the magnetic impurities went as p_αlnT on both sides of T_max. Above T_max the proportionality constant, p_α, was almost independent of n, and below T_max it was proportional to n². Applied magnetic fields had little effect on p_α even though T_max increased linearly with H. The magnitude of the resistivity at the peak was essentially independent of n but decreased for increased H. The superconducting transition temperature was depressed as n increased, but more slowly than predicted by Abrikosove and Gor'kov, and the critical field curves were considerably depressed below the multiple pair breaking theory of Fulde and Maki.

• Research Organization: Ames Lab., Ames, IA (United States)
• Sponsoring Organization: US Atomic Energy Commission (AEC)
• DOE Contract Number: W-7405-ENG-82
• NSA Number: NSA-24-047150
• OSTI ID: 4090171
• Report Number(s): IS-T--405
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CERIUM ALLOYS
CERIUM ALLOYS AND SYSTEMS/Ce--La
ELECTRIC CONDUCTIVITY
KONDO EFFECT
LANTHANUM ALLOYS
LANTHANUM ALLOYS AND SYSTEMS/Ce--La
MAGNETISM
SUPERCONDUCTIVITY
superconductivity and magnetic order in