DOPING OF THE QUADRUPLE PEROVSKITES OF TYPE ND(2)BA(2)CU(2)TI(2-X)M(X)O(11), M=MN, FE, CO, AL AND NDBA3CU2TI1-XO11(XNB1)

The synthesis of new ceramic materials NdBa3Cu2Ti1+xNb1-xO11 and Nd(2) Ba(2)Cu(2)Ti(2-x)M(x)O(11), M = Mn, Fe, Co, Al with a quadruple perovs kite structure was successfully performed, Rietveld refinements verifi ed the oxygen deficient layered a(p)a(p)*4a(p) superstructure (space group P4/mmm). Heterovalent doping in these groups of materials was ca rried out in order to provide a hole carrier concentration in the CuO2 layers structurally related to the high-T-c superconductors. However, superconductivity was not observed. The formation of oxygen defects i s discussed.