We report low-temperature thermal-expansion measurements on single crystals of the {\it layered} heavy fermion system \cri (0.3≤x≤0.6) and compare it with a previous study on the related {\it cubic} system \ci [R. K\"{u}chler {\it et al.}, Phys. Rev. Lett. {\bf 96}, 256403 (2006)]. Both systems display a quantum critical point as proven by a divergent Gr\"uneisen ratio. Most remarkably, the three-dimensional itinerant model explains quantum criticality in {\it both} systems, suggesting that the crystalline anisotropy in \cri is unimportant. This is ascribed to the effect of weak disorder in these doped systems.
@article{arxiv.0909.3460,
title = {Quantum criticality in layered CeRhIn_{5-x}Sn_x compared with cubic CeIn$_{3-x}Sn_x},
author = {J. G. Donath and F. Steglich and E. D. Bauer and F. Ronning and J. L. Sarrao and P. Gegenwart},
journal= {arXiv preprint arXiv:0909.3460},
year = {2009}
}