Ultrasonic study of the mixed-valence system YbIn{sub 1{minus}x}Ag{sub x}Cu{sub 4}
- Physikalisches Institut, Universitaet Frankfurt, Robert-Mayer Strasse 2-4, D-60054 Frankfurt (Germany)
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
- National High Magnetic Field Laboratory and Florida State University, Tallahassee, Florida 32306 (United States)
- Institute of Physics, Zagreb (Croatia)
We report ultrasonic investigation of the mixed-valence compounds YbIn{sub 1{minus}x}Ag{sub x}Cu{sub 4} for the different silver concentrations x=0, 0.2, 0.25, 0.3. This study enables us to characterize the coupling of the Yb ions with the lattice as a function of temperature, magnetic field, and silver concentration. For x=0 and 0.2 the system demonstrates pronounced first-order phase transition with the abrupt change in the different elastic moduli. For the higher silver concentrations we have observed rather smooth behavior of the elastic constants which is typical for a continuous phase transition. The critical temperature and the size of the anomaly in the bulk modulus at the phase transition changes linearly with silver concentration. External magnetic field shifts the transition to lower temperatures in accordance with previous investigations. Numerical calculations of the bulk modulus and the magnetic susceptibility have been performed in the frame of the promotional Ramirez-Falicov model. The results obtained demonstrate qualitative and quantitative agreement with the experimental data. {copyright} {ital 1999} {ital The American Physical Society}
- OSTI ID:
- 357299
- Journal Information:
- Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 5 Vol. 60; ISSN 0163-1829; ISSN PRBMDO
- Country of Publication:
- United States
- Language:
- English
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