We have studied the origin of subgrain formation in a melt-grown Y-Ba-Cu-O bulk. Micro structural observations suggest that the subgrains are associated with the dislocation walls formed by the amalgamation of dislocations which are created at the growth front when Y2BaCuO5 (Y211) particles are incorporated into the YBa2Cu3Oy, (Y123) matrix. The presence of subgrain-free regions near the growth sector boundaries shows that the subgrain structure is not formed with cellular growth. We suppose that the subgrain-free regions were formed during an incubation period of the growth, in which the dislocation density at the growth front is not high enough to assemble dislocation walls.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering