Superconductivity by transition metal doping in Ca₁₀(Fe_1−xM_xAs)₁₀(Pt₃As₈) (M= Co, Ni, Cu)

We report the successful substitution of cobalt, nickel, and copper for iron in the 1038 phase parent compound Ca$₁₀$(FeAs)$₁₀$(Pt$_3$As$_8$) yielding Ca$₁₀$(Fe$_1-x$Co$_x$As)$₁₀$(Pt$_3$As$_8$), Ca$₁₀$(Fe$_1-x$Ni$_x$As)$₁₀$(Pt$_3$As$_8$), and Ca$₁₀$(Fe$_1-x$Cu$_x$As)$₁₀$(Pt$_3$As$_8$), respectively. Superconductivity is induced in Co and Ni doped compounds reaching critical temperatures up to 15 K, similar to known Pt substituted Ca$₁₀$(Fe$_1-x$Pt$_x$As)$₁₀$(Pt$_3$As$_8$), whereas no superconductivity was detected in Ca$₁₀$(Fe$_1-x$Cu$_x$As)$₁₀$(Pt$_3$As$_8$). The obtained Tc(x) phase diagrams are very similar to those of other iron arsenide superconductors indicating rather universal behavior despite the more complex structures of the 1038-type compounds, where the physics is primarily determined by the FeAs layer.