Effect of pressure on the reentrant superconductor--normal-metal phase boundaries of the (La[sub 1[minus][ital n]]Ce[sub [ital n]])Al[sub 2] and (La[sub 1[minus][ital x]]Th[sub [ital x]])[sub 1[minus][ital n]]Ce[sub [ital n]] Kondo systems

Journal Article · Tue Feb 01 04:00:00 EST 1994 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.49.3894· OSTI ID:5294577

Ansari, P H; Bulman, J B; Huber, J G ^[1]; DeLong, L E ^[2]; Maple, M B ^[3]

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1. Department of Physics, Tufts University, Medford, Massachusetts 02155 (United States)
2. Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506 (United States)
3. Department of Physics and Institute for Pure and Applied Physical Sciences, University of California, San Diego, La Jolla, California 92093 (United States)

Measurements of the superconducting critical temperature [ital T][sub [ital c]]([ital n],[ital P]) as a function of Ce concentration [ital n] and pressure [ital P][le]20 kbar are reported for the superconducting Kondo systems (La[sub 1[minus][ital n]]Ce[sub [ital n]])Al[sub 2] and (La[sub 1[minus][ital x]]Th[sub [ital x]])[sub 1[minus][ital n]]Ce[sub [ital n]] (0[le][ital x][le]0.25). Data for the (La[sub 1[minus][ital n]]Ce[sub [ital n]])Al[sub 2] system are partially consistent with the theory of Mueller-Hartmann and Zittartz (MHZ), assuming an increase of [ital T][sub [ital K]]/[ital T][sub [ital c]0] with [ital P], where [ital T][sub [ital K]] is the Kondo temperature and [ital T][sub [ital c]0] is the critical temperature of the pure host superconductor. However, the pressure evolution of the reentrant superconducting-normal phase boundaries for the (La[sub 0.8]Th[sub 0.2])[sub 1[minus][ital n]]Ce[sub [ital n]] system is unexpected, and inconsistent with the MHZ theory. We find no evidence for the existence of a third transition (predicted by MHZ) back to the superconducting state for either the (La[sub 0.8]Th[sub 0.2])[sub 1[minus][ital n]]Ce[sub [ital n]] or (La[sub 1[minus][ital n]]Ce[sub [ital n]])Al[sub 2] systems. Recent Monte Carlo calculations by Jarrell may explain our data for both alloy systems, provided strong electron-phonon coupling effects are taken into account, although the effects of interimpurity interactions on the data remain uncertain.

• OSTI ID: 5294577
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 49:6; ISSN 0163-1829; ISSN PRBMDO
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104 -- Metals & Alloys-- Physical Properties
360107* -- Metals & Alloys-- Superconducting Properties-- (1992-)
ACTINIDE ALLOYS
ALLOYS
CERIUM ADDITIONS
CERIUM ALLOYS
DATA
INFORMATION
KONDO EFFECT
LANTHANUM ALLOYS
LANTHANUM BASE ALLOYS
NUMERICAL DATA
PHYSICAL PROPERTIES
PRESSURE DEPENDENCE
RARE EARTH ADDITIONS
RARE EARTH ALLOYS
STOICHIOMETRY
THEORETICAL DATA
THERMODYNAMIC PROPERTIES
THORIUM ALLOYS
TRANSITION TEMPERATURE
VERY HIGH PRESSURE