Non-Fermi-liquid behavior of YbCu 5 − x Al x

1999; American Physical Society; Volume: 60; Issue: 2 Linguagem: Inglês

10.1103/physrevb.60.1238

ISSN

1095-3795

Autores

E. Bauer, Robert G. Hauser, Andrei Galatanu, H. Michor, G. Hilscher, J.G. Sereni, M. Gómez Berisso, P. Pedrazzini, Mattéo Galli, F. Marabelli, P. Bonville,

Tópico(s)

Physics of Superconductivity and Magnetism

Resumo

A valency change in ${\mathrm{YbCu}}_{5\ensuremath{-}x}{\mathrm{Al}}_{x}$ from $\ensuremath{\nu}\ensuremath{\approx}2.2(x=0)$ to $\ensuremath{\nu}=3(x=2)$ causes a magnetic instability near a critical concentration ${x}_{\mathrm{cr}}\ensuremath{\approx}1.5.$ Alloys in the vicinity of ${x}_{\mathrm{cr}}$ exhibit typical non-Fermi-liquid properties like a negative logarithmic contribution to the specific heat or substantial deviations of the electrical resistivity from a ${T}^{2}$ behavior. Both pressure and alloying in this series bring about a strong reduction of the Kondo temperature ${T}_{K};$ the crystal-field interaction and the interatomic exchange gain therefore importance and magnetic order becomes possible beyond ${x}_{\mathrm{cr}}.$

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