EFFECTS OF OXYGEN-CONTENT ON THE SUPERCONDUCTING PROPERTIES OF MELT-TEXTURED LRE123 SUPERCONDUCTORS

The effects of oxygen content on the superconducting transition temper atures, T-c, and magnetic properties of melt-textured LRE123 (LRE = Nd , Sm) superconductors were studied. The oxygen content could be varied by changing the annealing temperature, T-a, in that the oxygen defici ency, delta, monotonically decreased with decreasing the T-a from 600 degrees C to 300 degrees C. A further decrease of T-c to 275 degrees C showed no appreciable change. In both systems the highest T-c was obt ained for the samples annealed at 300 degrees C. Magnetic properties w ere also strongly dependent on the oxygen content, showing that the co ntrol of oxygen content is critical for achieving good pinning propert ies. (C) 1997 Elsevier Science B.V.