Grain growth and microstructure of large-domain RE-systems prepared by mixture of Y-123 and RE-211 or 422 powders

We prepared Y-123 melt-textured bulk with Sm-211, Gd-211 and Nd-422 powders . The grain growth and the microstructure of single-domain (Y-123) + (RE-21 1 or 422) bulks were studied through scanning electron microscope and elect ron probe microanalyzer observations. Large-domains 10 mm in size were form ed in all the (Y-123) + (RE-211 or 422) systems using a seeding and tempera ture gradient method. The molar ratio of Y/RE changed at the interface betw een a single-domain and poly-grains. The molar ratio value of Y/Sm was simi lar to that of Y/Gd, while the molar ratio of Y/Nd was different from those of Y/Sm and Y/Gd. It was found that the substitution mechanism of RE eleme nts in the single-domain was dependent on the kind of RE elements for (Y-12 3) + (RE-211 or 422) system superconductors. (C) 2001 Elsevier Science B.V. All rights reserved.