The presence of valence fluctuating redox ions such as Pb, Tl, Sb, etc can enhance the transition temperature of the new oxide superconductors. We propose the possibility of the existence of negative Hubbard parameter (U) on redox ion which results in effective negativeU on apex oxygen bridging redox ion and the CuO2 planes. This enhancesTc.
Bulletin of Materials Science
Volume 43, 2020 All articles Continuous Article Publishing mode
