Very high trapped field in melt-processed Sm-Ba-Cu-O

We prepared c-axis oriented Sm-Ba-Cu-O bulk-superconductors by the melt-process technique in a reduced oxygen atmosphere. We particularly studied the effect of Ag addition to the composite in the present work, because Ag was found to greatly suppress the formation of macro-sized cracks in our earlier works. The samples were evaluated by measuring the residual magnetic flux density after field-cooling the samples. The trapped-field distributions mapped at 77 K show that samples with 10 or more wt.% Ag/sub 2/O consist of a single domain with no severe weak-links. The trapped magnetic flux density at the open surface of a sample with 20 wt.% Ag/sub 2/O and 30 mm in diameter was 8.0 T at 40 K. It was also found that the addition of Ag affects the microstructure of the sample and the distribution of the Sm/sub 2/BaCuO/sub 5/ phase was more homogeneous in samples with larger amount of Ag.