Influence of the pseudogap on the Nernst coefficient of Y0.9 Ca0.1Ba2Cu3OyM. Matusiak1, 2, S. H. Naqib1, 3, I. Kokanović1, 4 and J. R. Cooper1
1 Cavendish Laboratory, Department of Physics, University of Cambridge J. J. Thomson Avenue, Cambridge CB3 0HE, UK, EU
2 Institute of Low Temperature and Structure Research, Polish Academy of Sciences P.O. Box 1410, 50-950 Wrocław, Poland, EU
3 Department of Physics, University of Rajshahi - Raj-6205, Bangladesh
4 Department of Physics, Faculty of Science, University of Zagreb - P.O. Box 331, Zagreb, Croatia
received 23 December 2008; accepted in final form 15 March 2009; published April 2009
published online 20 April 2009
We have studied the Nernst coefficient, , of epitaxial thin films of the superconductor Y1-xCaxBa2Cu3Oy with x = 0.05 and x = 0.1. The x = 0.1 sample has been measured at three different values of y, in the over- (OV), optimally- (OP), and under-doped (UD) states. As the doping level is reduced, starts to fall linearly with T at the temperature (T*) where we expect to see the influence of the pseudogap. The onset temperature of the superconducting fluctuation contribution to was found to vary slowly with the hole concentration (p) between p = 0.118 and 0.197. For the OP and UD samples, is unusually large, being comparable with where S is the Seebeck coefficient and the Hall angle.
74.25.Fy - Transport properties (electric and thermal conductivity, thermoelectric effects, etc.).
74.72.Bk - Y-based cuprates.
72.15.Jf - Thermoelectric and thermomagnetic effects.
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