[en] Five superconductors of the Nd_1+xBa_2-xCu₃O_6.5±y type (x 0.00, 0.05, 0.10, 0.15, and 0.20) are prepared. The orthorhombic crystal lattice observed at x = 0 gradually transforms into a tetragonal structure at increasing values of x. Resistivity measurements (dc) show a metal-semiconductor type transition at temperatures above T_c. T_c ranges from 92 to 72 K by increasing values of x from 0.00 to 0.20, respectively. The oxygen content (y) increases with increasing x. Comparison of calculated and experimental values of y suggests that Nd is present in the form of Nd₂O₃. In contrast to earlier reports, it appears that the behavior observed are due to a mixture of Nd₂O₃ and NdBa₂Cu₃O_6.5±y instead of Nd_1+xBa_2-xCu₃O_6.5±y suggested earlier. (orig.)