We report on a comprehensive study of ${\mathrm{CePd}}_{1-x}{\mathrm{Rh}}_x$ ($0.6\le x\le 0.95$) 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 effects in both specific heat and thermal expansion, the Grüneisen ratio 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 $x\ge 0.65$, and the non-Fermi-liquid effects in the specific heat, ac susceptibility, and magnetization are compatible with the quantum Griffiths phase scenario.

• Received 19 September 2008

DOI:https://doi.org/10.1103/PhysRevLett.102.206404