The electrical resistivity of the heavy fermion superconductor Ce${}_2$PdIn${}_8$ was measured in magnetic fields up to 12 T and under hydrostatic pressures up to 21 kbar. At zero field, the low-temperature electrical resistivity in the normal state exhibits a power-law behavior ${\rho }_0+{\mathit{AT}}^n$ with $n<2$. In this non-Fermi-liquid regime, both the superconducting temperature $T_c$ and the coefficient $\mathrm{A=}$ decrease with increasing pressure, while the exponent $n$ and the resistivity maximum at $T_{max}$ increase. The findings indicate a destabilization of the superconducting state via increasing hybridization strength between the 4$f$ and conduction electrons. In concert, enlargement of the $f$-band width at the Fermi level results in a decrease of the density of states $N(E_F)$. Application of magnetic fields recovers the Fermi-liquid state at $H_{c2}$, at which both $A$ and ${\rho }_0$ show a tendency to diverge. The data obtained indicate that any change in the Kondo interaction strength in Ce${}_2$PdIn${}_8$ by applied pressure or quenching spin fluctuations by external magnetic fields results in pushing away the system from the non-Fermi-liquid regime concomitantly with the destruction of the superconducting state. These new results support a scenario in which the superconductivity in Ce${}_2$PdIn${}_8$ is driven by antiferromagnetic spin fluctuations in the vicinity of an underlying quantum critical point.

• Received 12 October 2010

DOI:https://doi.org/10.1103/PhysRevB.83.064504