Dresden 2006 – wissenschaftliches Programm
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TT: Tiefe Temperaturen
TT 25: Correlated Electrons - Poster Session
TT 25.58: Poster
Mittwoch, 29. März 2006, 14:30–18:30, P1
Ultra-low-temperature specific heat of CePd1−xRhx – smeared ferromagnetic quantum phase transition — •Adam Pikul, Tanja Westerkamp, Robert Kuechler, Nubia Caroca-Canales, Philipp Gegenwart, Julian Sereni, and Christoph Geibel — Max-Planck-Institut für Chemische Physik fester Stoffe, Dresden
The CePd1−xRhx system exhibits a continuous evolution from ferromagnetic (FM) order in CePd (TC = 6.5 K) to an intermediate–valence ground state in CeRh [1]. In the present contribution we report on results of low-temperature specific-heat measurements performed for polycrystalline samples of CePd1−xRhx, with the compositions 0.8 ≤ x ≤ 0.95, which are supposed to be close to a FM quantum critical point [1].
In contrast to CePd0.2Rh0.8, still demonstrating the FM phase transition at TC = 370 mK, the C(T) curve measured for CePd0.15Rh0.85 does not show any anomaly at least down to 70 mK. In the latter compound C/T ∼ −lnT, characteristic of a non-Fermi-liquid (NFL) system, and achieves a value of almost 1 J/(mol K2) at 70 mK. Upon further increasing of the Rh-content the value of C/T decreases, but the NFL behavior is still well visible in the samples with 0.87 ≤ x ≤ 0.95, for which C/T ∼ T−α (α ≈ 0.5). Upon applying magnetic fields FL behavior C/T(T) ∼ const. is recovered in all different samples.
The above-mentioned results indicate that the NFL behavior is observed down to mK-temperatures over an extended x-range (0.85 ÷ 0.95). This would be compatible with a smeared quantum phase transition.
A. Pikul’s attendance at this conference was sponsored by the Humboldt Foundation.
[1] J. G. Sereni, R. Küchler, C. Geibel, Physica B 359–361 (2005) 41