  We report the anomalous charge density wave (CDW) state evolution and
dome-like superconductivity (SC) in CuIr2Te4-xSex series. Room temperature
powder X ray-diffraction (PXRD) results indicate that CuIr2Te4-xSex compounds
retain the same structure as the host CuIr2Te4 and the unit cell constants a
and c manifest a linear decline with increasing Se content. Magnetization,
resistivity and heat capacity results suggest that superconducting transition
temperature (Tc) exhibits a weak dome-like variation as substituting Te by Se
with the maximum Tc = 2.83 K for x = 0.1 followed by suppression in Tc and
simultaneous decrease of the superconducting volume fraction. Unexpectedly, the
CDW-like transition (TCDW) is suppressed with lower Se doping but re-emerges at
higher doping. Meanwhile, the temperature-dependent XRD measurements show that
the trigonal structure is stable at 20 K, 100 K and 300 K for the host sample
and the doping composition with x = 0.5, thus we propose that the behaviour
CDW-like transition arises from the disorder effect created by chemical doping
and is not related to structural transition. The lower and the upper critical
fields of these compounds are also addressed.
