In-plane paraconductivity in a single crystal of superconducting YBa2Cu3O7-x

Abstract

Resistivity measurements have been made in the a-b plane on a single-crystal sample of superconducting YBa2Cu3O7-x. The resistivity versus temperature curve shows a highly linear region between 150 and 240 K, with an upward deviation from linearity at 240 K. With decreasing temperature below 150 K, the resistivity curve also deviates from linearity

this deviation has been analyzed in terms of the Aslamazov-Larkin, Lawrence-Doniach, and Maki-Thompson paraconductivity theories. All three theories can be fit to the data, but the Lawrence-Doniach model gives the best fit to the data, with physically reasonable parameters. We find that the Ginzburg-Landau coherence length in the c direction, extrapolated to low temperature with the theoretical temperature dependence, is approximately 0.44 A. © 1989 The American Physical Society.