Evidence of 3D-XY critical behaviour in La2-xSrxCuO4 films
IBM Research Division, Zurich Research Laboratory - 8803 Rüschlikon, Switzerland
2 Institut de Physique, Université de Neuchâtel - 2000 Neuchâtel, Switzerland
3 Département de Physique de la Matière Condensée, Université de Genève 1211 Genève, Switzerland
Accepted: 12 March 1996
We report measurements of the "zero field" ac sheet impedance for thin, c-axis–oriented films. For sufficiently thin films of thickness d, the magnetic penetration depth is given by . We find that the temperature and intriguing doping dependence of Lk as well as the amplitude of the perpendicular real-space phase correlation length are fully consistent with the critical behaviour of the three-dimensional XY model and finite-size scaling. Moreover, invoking finite-size scaling, we determine the value of the critical amplitude of .
PACS: 74.20.-z – Superconductivity: theory / 74.25.-q – General properties; correlations between physical properties in normal and superconducting states / 74.72.Dn – La-based compounds
© EDP Sciences, 1996