Abstract
The effects of Ag substitution for Bi, Sr and Cu on the c -axis lattice parameter and critical temperature ( T c ) were determined for the Bi 2− x Sr 2− y CaCu 2− z O 8+ δ (BSCCO-2212) superconducting phase. Two distinct regimes of behavior were observed: fast cooling represented the regime where the uptake of excess oxygen was the controlling factor and slow cooling represented the regime where the cation content was the controlling factor on the structure and properties. Samples showed higher T c values and longer c -axes with increased cooling rate. A linear increase in T c with increase in c -axis length was observed for the faster-cooled samples. For the slow-cooled samples, increased c -axis length was observed when Ag was substituted for Bi and Sr, whereas substituting Ag for Cu caused no change in c -axis length. In addition, any deviation from the ideal 2212 stoichiometry was shown to reduce the T c values of samples that were slowly cooled and fully oxygenated. Preliminary results obtained by high-resolution transmission electron microscopy coupled with electron energy loss spectroscopy indicated that relatively small amounts of Ag (≈1 at.%) can occupy Bi sites and a larger amount (≈10 at.%) of Ag can substitute for Cu.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.