Abstract
The paper is devoted to the microstructural defects in melt-processed YBaCuO which can be active either as magnetic-flux-pinning centers or weak links. The influence of 211 particles in 123-211 melt-textured bulk superconductors on the microstructural features such as microcracking, subgrains, twins, and twin complexes was studied by polarized light microscopy. The observed linear dependence between a-b microcrack spacing, and , and ⋅/ ( means 211 particle size, means 123 volume fraction, means 211 volume fraction) proves that the microcracking process can be described under the framework of a model devised for the multiple failure of a unidirectional composite under uniaxial tensile loading. Shorter mean-free distance between 211 particles depresses the subgrain thickness, the twin complex size, and twin spacing. The level of residual tensile stress in the 123 a-b plane was estimated from detwinning observed around 211 particles.
- Received 30 June 1995
DOI:https://doi.org/10.1103/PhysRevB.52.13658
©1995 American Physical Society