SUPERCONDUCTING OXYFLUORIDES ND2CUO4-XFX ND2-ZGDZCUO4-XFX AND PR2CUO4-XFX

Electron-doped superconductors Nd2CuO4-xFx ; Nd2-zGdz CuO4-xFx and Pr2 CuO4xFx have been synthesized. A single doping level (x bulk is simila r to 0.18) of F was used for all the samples. The Nd was also substitu ted with Gd at z=0.05; 0.20 and 0.50. The fluorination of the Nd; NdGd and Pr cuprates (oxidized propionates) was made in a vacuum furnace. Except for the sample with highest Gd content, dc magnetization measur ements detected superconducting transition in all these samples with T (c) is similar to 26 K, independent of the choice of Ln. In some of th e fluorinated Nd-cuprates a second, very weak superconducting phase tr ansition has been revealed at 35 K.