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Growth of single‐grain GdBa 2 Cu 3 O 7‐x superconductors by top seeded infiltration and growth technique
Author(s) -
Li GuoZheng,
Yang WanMin,
Tang YaoLong,
Ma Jun
Publication year - 2010
Publication title -
crystal research and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.377
H-Index - 64
eISSN - 1521-4079
pISSN - 0232-1300
DOI - 10.1002/crat.200900365
Subject(s) - nucleation , materials science , microstructure , supercooling , grain growth , superconductivity , seeding , crystallization , fabrication , grain size , crystal growth , analytical chemistry (journal) , crystallography , chemical engineering , composite material , condensed matter physics , thermodynamics , chemistry , chromatography , medicine , physics , alternative medicine , pathology , engineering
The top seeded infiltration and growth technique (TSIG) is an effective way for the preparation of bulk REBa 2 Cu 3 O 7‐x (RE‐123, where RE denotes rare earth) with finely dispersed RE 2 BaCuO 5 (RE‐211) particles compared to the conventional melt growth (MG) method. The nucleation temperature and the ending growth temperature are the most important parameters need to be optimized during the preparation of RE‐123 bulks by the TSIG process. In this paper, the effects of these parameters on the growth of single‐grain GdBa 2 Cu 3 O 7‐x (GdBCO) superconductors have been investigated experimentally. It is found that the temperature for the growth of single‐grain GdBCO is in the region between 1040 °C and 1015 °C. In addition, the relation between growth rate and supercooling has been investigated in detail. The combined techniques of SEM and EDS were used to study the microstructure of the samples grown at different temperatures. Based on this, a two‐step slow cooling method during the crystallization process is proposed for the fabrication of RE‐123 bulks. Finally, the single‐grain GdBCO samples of the diameters 20 mm and 30 mm were fabricated successfully by the TSIG technique, with the slow‐cooling process in the temperature window 1030 °C–1020 °C for 60 h and 100 h respectively. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)