Characterization of doped Nd-based superconductors

Y-, Dy-, and Gd-doped neodymium (Nd) superconductors (RE_0.1Nd_0.9Ba₂-Cu₃O_y) exhibited sharp resistivity transitions at 92 K. DC susceptibility measurements gave a common curve with diamagnetic onsets at 93 K and transitions complete at ≈50 K. Lattice constants for an assumed orthorhombic structure were calculated from X-ray diffraction measurements. These values were used to create a simulated diffraction pattern with 2 θ values and relative intensities that agreed well with observed values. Oxygen contents determined by instrumental neutron activation analysis, ranged from 14.7 to 15.1±0.1 wt%(6.59≤y in O_y≤6.73). This range of oxygen content for YBa₂Cu₃O_y gives ≈50-60 K transitions in marked contrast to the 92 K (midpoint) values for the materials of this study.