Acoustic emission study of microcracking in 123-type ceramic superconductors
- 1 October 1990
- journal article
- Published by Springer Nature in Journal of Materials Research
- Vol. 5 (10), 2066-2074
- https://doi.org/10.1557/jmr.1990.2066
Abstract
Acoustic emission from sintered ceramic YBa2Cu3O7−x (YBCO) superconductor pellets provides a direct measure of microcracking behavior during processing. By detection and statistical analysis of acoustic events, the effects of cooling rates, processing atmosphere, average grain size, additives, and grain alignment on microcracking in YBCO have been studied. The onset temperature and duration of acoustic emission during cooling correlate well with the oxygen partial pressure in the furnace. Rapid changes in oxygen partial pressure at constant temperature produce acoustic emission that is characteristic of microcracking. A reported critical grain size for microcracking in sintered polycrystalline YBCO of about 1 μm has been confirmed. Two superconducting compounds, YSrBaCu3O7−x and LaBaCaCu3O7−x with the 123 structure but with smaller crystallographic anisotropy were also examined. Recommendations are made for minimizing microcracking during processing of superconducting ceramics.Keywords
This publication has 36 references indexed in Scilit:
- Effects of room-temperature pressure cycling on the critical currents in a YBa2Cu3O7−δ superconductorJournal of Applied Physics, 1989
- The effect of grain size on microstructure and stress relaxation in polycrystalline Y1Ba2Cu3O7−δJournal of Materials Research, 1989
- Detection of surface (∼1 μm) impurity phases in high T c superconductorsApplied Physics Letters, 1989
- The effect of non-superconducting interfaces on the electrical transport properties of high-TcY1Ba2Cu3O7-xbulk oxidesSuperconductor Science and Technology, 1988
- Correlation of grain boundary defect structure with boundary orientation in Ba2YCu3O7−xApplied Physics Letters, 1988
- XPS study of the grain boundary phase in YBa2Cu3O7−δPhysica C: Superconductivity and its Applications, 1988
- Densification and microstructural studies on Y-Ba-Cu-O superconducting oxideSuperconductor Science and Technology, 1988
- Small field behavior of critical current in Y1Ba2Cu3O7 sintered samplesApplied Physics Letters, 1988
- Orientation Dependence of Grain-Boundary Critical Currents inBicrystalsPhysical Review Letters, 1988
- Experiments concerning the connective nature of superconductivity in YBa2Cu3O7Journal of Applied Physics, 1987