Optimization of the binder addition methods for bulk Y-Ba-Cu-O superconductors

Recent studies have revealed that an addition of binder such as acrylic is effective in reducing cracking during the preparation processes of the precursors and thus in promoting the grain growth of good quality bulk superconductors. However, when the distribution of binder is not uniform, some defects are introduced in the precursors and thereby the grain growth is inhibited. At present, the optimum conditions for mixing binders and precursor superconducting raw materials are not yet established. In this work, we have studied the effects of the liquid binder addition on the superconducting properties and the grain growth behavior of bulk Y-Ba-Cu-O superconductors about 40 mm in diameter produced with the top-seed melt-growth process. We have found that optimized binder additions contribute to the consolidation of the bulk precursor and further to the grain growth of single-grain bulk superconductors.