Thermodynamics of the first-order valence transition in YbInCu{sub 4}

Journal Article · Wed Jul 01 04:00:00 EDT 1998 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.58.409· OSTI ID:636183

Sarrao, J. L. ^[1]; Ramirez, A. P. ^[2]; Darling, T. W.; Freibert, F.; Migliori, A. ^[1]; Immer, C. D.; Fisk, Z. ^[3]; Uwatoko, Y. ^[4]

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1. Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
2. Bell Laboratories, Lucent Technology, Murray Hill, New Jersey 07974 (United States)
3. National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32306 (United States)
4. Department of Physics, Saitama University, Urawa, Saitama 338 (Japan)

We present measurements of the specific heat and complete elastic moduli of YbInCu{sub 4} as a function of temperature in order to complement existing thermal expansion data. Together these data allow a complete analysis of the thermodynamics of the first-order isostructural valence transition in YbInCu{sub 4}. The Clausius-Clapeyron equation predicts well the measured pressure dependence of the valence transition temperature. Estimates of the Gruneisen parameter from thermodynamic measurements and from pressure-dependent magnetic susceptibility in both the high-temperature and low-temperature phases of YbInCu{sub 4} are in good agreement. On the other hand, a Gruneisen analysis of the change in Kondo temperature at the valence transition fails, emphasizing the importance of carrier-density changes associated with the valence transition, unlike in the case of the {gamma}-{alpha} transition in elemental Ce. Finally, we address the issue of precursive rounding in the elastic moduli for temperatures greater than the valence transition temperature and argue that thermodynamically YbInCu{sub 4}{close_quote}s valence transition is indeed first order. {copyright} {ital 1998} {ital The American Physical Society}

• Sponsoring Organization: USDOE
• OSTI ID: 636183
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 1 Vol. 58; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COPPER ALLOYS
ELASTICITY
GRUENEISEN CONSTANT
INDIUM ALLOYS
KONDO EFFECT
MAGNETIC SUSCEPTIBILITY
SPECIFIC HEAT
THERMAL EXPANSION
THERMODYNAMIC PROPERTIES
THERMODYNAMICS
VALENCE
YTTERBIUM ALLOYS