Connections between magnetism and superconductivity in UBe13 doped with thorium or boron
- Los Alamos National Lab., NM (USA)
Magnetism and superconductivity appear to be intimately connected in the heavy electron (HE) superconductors. For example, it has been conjectured but not proven that the exchange of antiferromagnetic spin fluctuations are responsible for pairing in HE superconductors. In this paper we review recent results in U{sub 1-x}Th{sub x}Be{sub 13}, where specific heat, lower critical field and zero-field {mu}SR measurements reveal another second-order phase transition to a state which possesses small-moment magnetic correlations for 0.019 {le} {times} {le} 0.043. We present a new phase diagram for (U,Th)Be{sub 13} which indicates that the superconducting and magnetic order parameters are closely coupled. A discussion of the nature of the lower phase is presented, including the consideration of a possible magnetic superconducting state. When UBe{sub 13} is doped with B (UBe{sub 12.97}B{sub 0.03}) the Kondo temperature is decreased and the specific heat jump at the superconducting transition temperature is significantly enhanced. However, {mu}SR measurements reveal no magnetic signature in UBe{sub 12.97}B{sub 0.03}, unlike the case for Th doping. The correlation between changes in the Kondo temperature and changes in the superconducting properties induced by B doping provide evidence for the importance of magnetic excitations in the superconducting pairing interaction in UBe{sub 13}.
- Research Organization:
- Los Alamos National Lab., NM (USA)
- Sponsoring Organization:
- DOE; USDOE, Washington, DC (USA)
- DOE Contract Number:
- W-7405-ENG-36
- OSTI ID:
- 5965836
- Report Number(s):
- LA-UR-91-1381; CONF-910608--1; ON: DE91011416
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
360104* -- Metals & Alloys-- Physical Properties
656100 -- Condensed Matter Physics-- Superconductivity
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ACTINIDE COMPOUNDS
ACTINIDES
ALKALINE EARTH METAL COMPOUNDS
ANGULAR MOMENTUM
BERYLLIUM COMPOUNDS
BORON
DOPED MATERIALS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELEMENTS
KONDO EFFECT
MAGNETISM
MATERIALS
METALS
PARTICLE PROPERTIES
PHYSICAL PROPERTIES
SEMIMETALS
SPECIFIC HEAT
SPIN
SUPERCONDUCTIVITY
TEMPERATURE DEPENDENCE
THERMODYNAMIC PROPERTIES
THORIUM
TRANSITION TEMPERATURE
URANIUM COMPOUNDS