Homologous series of (Cu,Mo)Sr2(Y,Ce)sCu2O5+2s+δ copper-oxide superconductors: Synthesis of members up to s=6

► (Cu,Mo)Sr2Y Ces−1Cu2O5+2s+δ or (Cu,Mo)-12s2 superconductors form a homologous series. ► Members of the series differ from each other by the number s of (Y, Ce) cation layers. ► Phases up to s=6 have been synthesized through slow layer-intercalation reactions. ► With increasing s and thickness of the (Y, Ce)-[O2-(Y,Ce)]s−1 block Tc remains constant.