Growth and physical properties of top-seeded infiltration growth processed large grain (Gd, Dy)BCO bulk superconductors

• Published in: Journal of applied physics 2017-11, Vol.122 (19)
• Main Authors: Pavan Kumar Naik, S., Muralidhar, M., Jirsa, M., Murakami, M.
• Format: Article
• Language: English
• Subjects: Applied physics; Critical current density; Crystal growth; Dependence; Dwell time; Dysprosium; Gadolinium; Grain growth; Infiltration; Microstructure; Physical properties; Superconductivity; Superconductors; Supercooling
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/1.4999164

The primary prerequisite for successful single grain growth of a REBa2Cu3Oy bulk superconductor is the determination of an optimized growth temperature window of the given system. In our recent work, addition of 20 wt. % of Dy2BaCuO5 (Dy-211) to the GdBa2Cu3O7-δ bulk sample [(Gd,Dy)BCO] enhanced superconducting properties. Then, different isothermal dwell times were tested at various undercooling temperatures to find the temperature window appropriate for the single grain growth by a top-seeded infiltration growth process performed in air. Nearly perfect single-grain (Gd,Dy)BCO crystals were grown. A systematic and detailed investigation of the microstructure, composition, and physical properties of the single-grain (Gd,Dy)BCO superconductors was carried out. The superconducting transition was sharp with the onset at 92.9 K. The field dependence of the critical current density (Jc ) was determined at several temperatures. At 77 K, a self-field Jc of 55 kA/cm2 and a trapped field of 0.19 T were achieved. The possibilities for further improvement of the microstructure and superconducting performance are discussed.