We report measurements of electrical resistivity, magnetic susceptibility, specific heat, and thermoelectric power on the system Pr1-xCexPt4Ge12. Superconductivity is suppressed with increasing Ce concentration up to x = 0.5, above which there is no evidence for superconductivity down to 1.1 K. The Sommerfeld coefficient {\gamma} increases with increasing x from 48 mJ/mol K^2 up to 120 mJ/mol K^2 at x = 0.5, indicating an increase in strength of electronic correlations. The temperature dependence of the specific heat at low temperatures evolves from roughly T^3 for x = 0 to e^(-\Delta /T) behavior for x = 0.05 and above, suggesting a crossover from a nodal to a nodeless superconducting energy gap or a transition from multiband to single-band superconductivity. Fermi-liquid behavior is observed throughout the series in low-temperature magnetization, specific heat, and electrical resistivity measurements.
@article{arxiv.1403.5329,
title = {Probing the superconductivity of PrPt4Ge12 through Ce substitution},
author = {K. Huang and L. Shu and I. K. Lum and B. D. White and M. Janoschek and D. Yazici and J. J. Hamlin and D. A. Zocco and P. -C. Ho and R. E. Baumbach and M. B. Maple},
journal= {arXiv preprint arXiv:1403.5329},
year = {2014}
}