FLUX PINNING EFFECTS IN Ag-DOPED YBCO (123) SUPERCONDUCTOR

Abstract

Polycrystalline samples of Ag+-doped YBCO (123) (YBa2 (Cu1-xAgx)3O7-δ)with 0≤x≤0.3 were produced by solid state reaction method. The Ag- doped YBCO samples showed higher critical current densities (Jc) with a Jc maximum for samples doped with x=0.05. This behavior can be assigned to an increase of pinning forces. The irreversibility temperature (Tirr), also increased in doped samples as a function of Ag content, with the highest temperature for the sample doped with x=0.05, wich correlates well with the observed Jc increasing. However, samples doped with x>0.05 displayed a decreasing of electrical properties (less Tirr, less Jc, etc.) atributed to an excess of Ag in the grain boundaries which, reduces the grain sizes and increases the number of weak- links.

Keywords

• Fuerza de anclaje
• irreversibilidad magnética
• corriente crítica
• superconductores dopados.