Effect of oxygen deficiency on the thermoelectric power and the resistive transition is studied by changing the cooling rate of the sintered specimens of R1Ba2Cu3O7−x where R=Y, Gd and Sm. Slow-cooled (60°C/h) specimens are superconducting and show positive TEP with a broad peak aboveTc. It is a decreasing function of temperature at higher temperatures. Pair fluctuation aboveTc is thought to be responsible for this peak. Highly O2-deficient sample of Y123 has a finite resistivity atTc and yet shows a zero TEP. It is suggested that the percolation concentration of the superconducting phase for zero TEP should be much smaller than that required for the electrical conduction.
Volume 43, 2020
Continuous Article Publishing mode
Prof. Subi Jacob George — Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru
Chemical Sciences 2020
Prof. Surajit Dhara — School of Physics, University of Hyderabad, Hyderabad
Physical Sciences 2020
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