The metallic conductivity of both the CuO2 sheets and the CuOx chains of YBa2Cu3O7-δ has been established. We have used double doping in (Y1-xCax)(Ba2-xLax)Cu3O7-δ to destroy the integrity of the CuO1-δ chains while keeping constant the total oxidation state of the Cu-O array. A break-up of the chain segments allows us to establish the temperature dependence of the Seebeck coefficient, α(T), due to the CuO2 sheets and, by difference, that of the CuO1-δ chains in YBa2Cu3O7-δ. We also show that double doping enhances significantly the chemical stability of the superconductive phase. The origin of the chemical stability and of the behavior of α(T) is interpreted.
- High-T superconductor
- chain conduction
- chemical stability
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Physics and Astronomy (miscellaneous)