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Effect of mesoscopic inhomogeneities on the critical current of bulk melt-textured YBCO

L. S. Uspenskaya·I. G. Naumenko·G. A. Emelchenko·Yu. B. Boguslavskii·S. A. Zverkov·E. B. Yakimov·D. Litzkendorf·W. Gawalek·A. D. Caplin
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Abstract

The downsizing 211-inclusions and an increase of their density leads to rise in mean critical current value in Y-based melt textured material. Very often 211-inclusion are spread in the material volume non-homogeneous, with typical scale 50 - 100 micrometer. Therefore it is difficult to find the real correlation between local critical current and the inclusions distribution. We performed a study of a local critical current using modified magneto-optic technique on a melt-textured YBaCuO ceramic, found the areas with constant current and studied the real structure of the material in the areas, inclusions distribution and their sizes, by scanning electron microscopy and X-ray microanalysis. The estimation of a pinning in these places, by taking into account the amount of inclusions and the length of their boundaries, and comparison with the value of local critical current reveals a strait correlation between the density of inclusions and the current but shows remarkable quantitative disagreement.

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L. S. Uspenskaya, I. G. Naumenko, G. A. Emelchenko, Yu. B. Boguslavskii, S. A. Zverkov, E. B. Yakimov, D. Litzkendorf, W. Gawalek, A. D. Caplin. 2003-03-16. Effect of mesoscopic inhomogeneities on the critical current of bulk melt-textured YBCO. https://doi.org/10.1016/s0921-4534(03)00629-4

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