Controlled Heterogeneous Nucleation of Melt-Textured YBa2Cu3O6+x by Addition of Al2O3 Particles
Abstract
The reaction between alumina and yttrium barium cuprate subjected to a melt-texturing heat-treatment was studied. Microstructural examination of quenched, partially transformed samples revealed that at approx. 1050 deg C (which is above the incongruent melting temperature of YBa2Cu3O6+x), a reaction layer forms at the alumina interface. The reaction products were identified as Ba6y2A14015 and a copper-rich liquid phase. On cooling below the peritectic temperature, aligned domains of YBa2Cu3O6+x (123) were observed to preferentially nucleate at the reaction layer. For samples of melt-textured 123 deliberately seeded with alumina particles, it was found that nucleation and growth of 123 occurred exclusively at the particles. A reaction sequence for the formation of the Ba6y2A14015 is put forward, together with a discussion of the possible nucleation mechanisms for the 123. Yttrium Barium Copper Oxide(YBCO), Peritectic, Melt-texturing, Nucleation, Barium Yttrium Aluminum Oxide (Ba6y2A14015)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1992
- Accession Number
- ADA274605
Entities
People
- Helen M. Chan
- Lijie Zhang
- Martin P Harmer
- Yan L. Chen
Organizations
- Lehigh University