Nanophase Al2O3 powders were added to TlBa2Ca2Cu3Ox powders in 20 mol.% concentrations. Pellets produced from powders with and without nanophase oxides were heated in O2 above the peritectic melting temperatures and cooled at 10°C/h. For temperatures ≤ 35 K, the intragranular critical current density, Jc, increased dramatically for all specimens with the Al2O3 additions. However, no significant changes in Jc with Al2O3 additions were observed at 77 K. The enhancement in Jc appears to be associated with the presence of nanometer-sized inclusions in the superconductor. The pinning by the inclusions can be understood by considering the interaction between flux lines and cavities. It is shown that for pinning by such cavities to be effective, the cavities must be small, numerous, and well-distributed.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering