Effect of size, morphology and crystallinity of seed crystal on the nucleation and growth of single grain Y–Ba–Cu–O

Autor:	N. Hari Babu, E Sudhakar Reddy, David A. Cardwell, Yunhua Shi
Rok vydání:	2005
Předmět:	Materials science Nucleation Analytical chemistry Mineralogy Grain growth Crystallinity Condensed Matter::Superconductivity Phase (matter) Materials Chemistry Ceramics and Composites Seeding Grain boundary Texture (crystalline) Seed crystal
Zdroj:	Journal of the European Ceramic Society. 25:2935-2938
ISSN:	0955-2219
DOI:	10.1016/j.jeurceramsoc.2005.03.228
Popis:	The effect of size, morphology and crystallinity of seed crystals on the nucleation and growth of large grain Y–Ba–Cu–O (YBCO) bulk superconductors fabricated by top seeded melt growth (TSMG) has been investigated. Seeding bulk samples with small, square shaped seed crystals leads to point nucleation and growth of the superconducting YBa 2 Cu 3 O 7− y (Y-123) phase that exhibits the usual square habitual growth symmetry. The use of triangular and circular shaped seed crystals, however, modifies significantly the growth habit geometry of the grain. The use of large area seeds both increases the rate of epitaxial nucleation of the Y-123 phase and produces relatively large crystals in the incongruent melt, which decreases significantly the processing times of large grain samples. The present study is relevant to decrease processing times of samples with both preferred or no growth sectors and for multiple seeding of large grain samples which contain clean grain boundaries.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::08ece27d3d1a4ddab08e60f38490ee54 https://doi.org/10.1016/j.jeurceramsoc.2005.03.228 Zobrazit plný text záznamu Full Text from ScienceDirect