Kondo-Cluster-Glass State near a Ferromagnetic Quantum Phase Transition

Autor: Westerkamp, T., Deppe, M., Kuechler, R., Brando, M., Geibel, C., Gegenwart, P., Pikul, A. P., Steglich, F.
Rok vydání: 2009
Předmět:
Zdroj: Phys. Rev. Lett. 102, 206404 (2009)
Druh dokumentu: Working Paper
DOI: 10.1103/PhysRevLett.102.206404
Popis: We report on a comprehensive study of CePd$_{1-x}$Rh$_x$ $(0.6 \leq x \leq 0.95)$ poly- and single crystals close to the ferromagnetic instability by means of low-temperature ac susceptibility, magnetization and volume thermal expansion. The signature of ferromagnetism in this heavy-fermion system can be traced from 6.6 K in CePd down to 25 mK for $x=0.87$. Despite pronounced non-Fermi-liquid (NFL) effects in both, specific heat and thermal expansion, the Gr\"uneisen ratio {\it does not} diverge as $T\to 0$, providing evidence for the absence of a quantum critical point. Instead, a peculiar "Kondo-cluster-glass" state is found for $x\geq 0.65$, and the NFL effects in the specific heat, ac susceptibility and magnetization are compatible with the quantum Griffiths phase scenario.
Comment: 4 pages, 4 figures
Databáze: arXiv