Slow crossover in YbXCu{sub 4} (X = AgCd, In, Mg, Tl, Zn) intermediate valence compounds

Journal Article · Wed Jun 07 04:00:00 EDT 2000 · Physical Review B. Condensed Matter and Materials Physics

OSTI ID:776598

Lawrence, J M ^[1]; Riseborough, P S; Booth, C H; Sarrao, J L; Thompson, J D; Osborn, R

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1. LBNL Library

We compare the results of measurements of the magnetic susceptibility {chi}(T), the linear coefficient of specific heat {gamma}(T)=C(T)/T and 4f occupation number n{sub f}(T) for the intermediate valence compounds YbXCu{sub 4} (X = Ag, Cd, In, Mg, Tl, Zn) to the predictions of the Anderson impurity model, calculated in the non-crossing approximation (NCA). The crossover from the low temperature Fermi liquid state to the high temperature local moment state is substantially slower in the compounds than predicted by the NCA; this corresponds to the ''protracted screening'' recently predicted for the Anderson Lattice. We present results for the dynamic susceptibility, measured through neutron scattering experiments, to show that the deviations between theory and experiment are not due to crystal field effects, and we present x-ray-absorption fine-structure (XAFS) results that show the local crystal structure around the $$X$$ atoms is well ordered, so that the deviations probably do not a rise from Kondo Disorder.

• Research Organization: Lawrence Berkeley National Lab., CA (US)
• Sponsoring Organization: USDOE Director, Office of Science. Office of Basic Energy Studies (US)
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 776598
• Report Number(s): LBNL--46027
• Journal Information: Physical Review B. Condensed Matter and Materials Physics, Journal Name: Physical Review B. Condensed Matter and Materials Physics Journal Issue: 5 Vol. 63
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ATOMS
CRYSTAL FIELD
CRYSTAL STRUCTURE
FERMI GAS
FINE STRUCTURE
MAGNETIC SUSCEPTIBILITY
MIXED VALENCE XAFS NON-CROSSING APPROXIMATION
NEUTRONS
SCATTERING
SPECIFIC HEAT
VALENCE