  We report the effect of Pt doping on the superconductivity in CuRh2Se4 spinel
using a combined experimental and theoretical study. Our XRD results reveal
that the Cu(Rh1-xPtx)2Se4 crystallizes in the structure with a space group of
Fd3-m (No. 227), and the lattice parameter a increases with Pt doping. The
resistivity and magnetic susceptibility measurement results verify that the
superconducting transition temperature (Tc) forms a dome-like shape with a
maximum value of 3.84 K at x = 0.06. It is also observed that the Pt-doping
slightly reduces the lower critical magnetic field from 220 Oe in CuRh2Se4 to
168 Oe in Cu(Rh0.94Pt0.06)2Se4, while it significantly enhances the upper
critical magnetic field, reaching the maximum of 4.93 T in the
Cu(Rh0.94Pt0.06)2Se4 sample. The heat capacity result indicates that the sample
Cu(Rh0.91Pt0.09)2Se4 is a bulk superconductor. First-principles calculations
suggest that the Pt-doping leads to a red-shift of a density of state peak near
the Fermi level, consistent with the dome-like Tc observed experimentally.
