High quality (Sm,Eu,Gd)Ba2Cu3O7-δ single domain superconductors were grown in air with BaCuO2-x addition. The flux pinning was investigated with varying temperatures of Ar post-annealing and the Eu/Gd ratio in the initial composition. The amplitude of the peak effect displayed a peak when annealed at 925 °C in Ar while the irreversible field Birr keeping unchanged. Eu enrichment dramatically enhanced Birr and the peak field for the samples annealed at 925 °C in Ar. At 77 K Birr was higher than 9 T in (Sm0.33Eu0.44Gd0.22)Ba2Cu 3O7-δ. Structural characterization showed that the average size of (Sm,Eu,Gd)2BaCuO5 inclusions slightly decreased with increasing the Gd concentration. The scaling analysis and field dependence of superconducting transition evidenced a predominant δT c style pinning induced by local compositional fluctuation. The evolution of flux pinning was thus attributed to variable compositional fluctuation.
ASJC Scopus subject areas