Morphological stability of Sm123 superconductor during peritectic solidification from Sm211 + L mixture

• Published in: Metallurgical and materials transactions. B, Process metallurgy and materials processing science Vol. 31; no. 1; pp. 141 - 149
• Main Authors: SUMIDA, M, SHIOHARA, Y, UMEDA, T
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer 01.02.2000; Springer Nature B.V
• Subjects: BARIUM OXIDES; COPPER OXIDES; Cross-disciplinary physics: materials science; rheology; CRYSTAL STRUCTURE; Exact sciences and technology; HIGH-TC SUPERCONDUCTORS; MATERIALS SCIENCE; Phase diagrams and microstructures developed by solidification and solid-solid phase transformations; Physics; SAMARIUM OXIDES; SOLIDIFICATION; YTTRIUM OXIDES; Samarium oxides; Critical current density; Structure stability; Local equilibrium; Experimental study; Cuprates; Solidification; Monocrystals; Superconductors; Morphology; High-Tc superconductors; Crystal nucleation; Supercooling; SEM
• ISSN: 1073-5615; 1543-1916
• DOI: 10.1007/s11663-000-0139-3

The interface stability of the Sm 123 superconductor was analyzed in accordance with the constitutional undercooling criterion. As the single-crystal growth of the 123 phase is largely dependent on the growth-interface stability, a quantitative analysis was very much required. From this analysis, it was clarified that the constitutional undercooling must exist in the liquid when the 123 growth interface comes close to a 211 particle during the peritectic solidification. It was also predicted that the larger 211 particle radius, smaller volume fraction of the 211 particles, larger growth rate, or smaller imposed temperature gradient would cause easy occurrence of the constitutional undercooling ahead of the 123 growth interface. Taking into account the nucleation at the L/211 interface just ahead of the 123 growth front due to the constitutional undercooling, the transition of 123 growth from a planar-interface morphology to an equiaxed blocky morphology was investigated quantitatively and qualitatively.