A new seeding approach to the melt texture growth of a large YBCO single domain with diameter above 53 mm

摘要

A new approach for growing large size single domains of Y-Ba-Cu-O by a top-seeded melt-textured growth (TSMTG) process is reported. Contrary to the commonly used TSMTG method using a small seed crystal that has been difficult to use to grow well-textured single domains with diameters above 50 mm, we adopt a large well-textured SmBCO bulk with a size of 14 x 14 mm(2) as a seed to grow YBCO single domains. Experimental results show that this new approach can not only quicken the growth rate of the bulk, but also result in a better textured structure. By using this method, large YBCO single domains of up to 53 mm in diameter have been successfully produced and 75 mm diameter samples can also be grown. Microstructure analysis of these as-grown YBCO bulks shows a good c-axis orientation in crystallization, and magnetic levitation force measurements show that the bulks 53 mm in diameter have excellent magnetic levitation performance, with levitation force of up to 334 N (77 K, 0.5 T), corresponding to a force density of 15.2 N cm(-2).