SUPERCONDUCTING PROPERTIES OF YBA2CU3O7-DELTA WITH PARTIAL RARE-EARTH SUBSTITUTION

Superconducting properties of the YBa2Cu3O7-delta compound with partial rare earth substitution (20 atomic pct substitution for yttrium) have been studied. Among the 14 rare earth elements investigated, La, Ce and Pr caused suppression in T(c), while other elements had no effect. Some of the rare earths (Sm, Gd, Eu), when partially substituted for Y, resulted in a slight improvement in intragrain J(c) (flux pinning) as measured magnetically. Although the rare earth elements have widely different ionic radii, all the (RE) Ba2Cu3O7-delta phases have found to be soluble in YBa2Cu3O7-delta with no dectable segregation observed by SEM and energy dispersive X-ray analysis.