  We report on a pressure-induced evolution of exotic superconductivity and
spin correlations in CeIr(In$_{1-x}$Cd$_{x}$)$_5$ by means of
In-Nuclear-Quadrupole-Resonance (NQR) studies. Measurements of an NQR spectrum
and nuclear-spin-lattice-relaxation rate $1/T_1$ have revealed that
antiferromagnetism induced by the Cd-doping emerges locally around Cd dopants,
but superconductivity is suddenly induced at $T_c$ = 0.7 and 0.9 K at 2.34 and
2.75 GPa, respectively. The unique superconducting characteristics with a large
fraction of the residual density of state at the Fermi level that increases
with $T_c$ differ from those for anisotropic superconductivity mediated by
antiferromagnetic correlations. By incorporating the pressure dependence of the
NQR frequency pointing to the valence change of Ce, we suggest that
unconventional superconductivity in the CeIr(In$_{1-x}$Cd$_{x}$)$_5$ system may
be mediated by valence fluctuations.
