  Magnetic susceptibility, electrical resistivity and heat capacity data for
single crystals of Ce(Rh,Ir)1-x(Co,Ir)xIn5 (0 < x < 1) have allowed us to
construct a detailed phase diagram for this new family of heavy-fermion
superconductors(HFS). CeRh1-xIrxIn5 displays superconductivity(SC) (Tc < 1 K)
over a wide range of composition, which develops out of and coexists (0.30 < x
< 0.5) with a magnetically ordered state, with TN ~ 4 K. For CeCo1-xRhxIn5, the
superconducting state (Tc ~ 2.3 K for x = 0) becomes a magnetic state (TN ~ 4
K, for x = 1) with two phase transitions observed for 0.40 < x < 0.25.
CeCo1-xIrxIn5 also shows two transitions for 0.30 < x < 0.75. For those alloys
in which SC is found, a roughly linear relationship between Tc and the lattice
parameter ratio c/a, was found, with composition as the implicit parameter. The
interplay between magnetism and SC for CeRh1-x(Ir,Co)xIn5 and the possibility
of two distinct superconducting states in CeCo1-xIrxIn5 are discussed.
