title: Comparison of the scaling analysis of mixed-state magnetization data with direct measurements of the upper critical field for YBa(2)Cu(3)O(7-x).
abstract: By comparison of recent direct measurements of the temperature dependence of the upper critical field H(c2) of an YBa(2)Cu(3)O(7-x) high-T(c) superconductor with the scaling analysis of magnetization data, collected in fields [Formula: see text], we demonstrate that the temperature dependence of the Ginzburg-Landau parameter κ is negligible. Another conclusion is that the normalized temperature dependence of H(c2) is independent of the orientation of the magnetic field with respect to the crystallographic axes of the sample. We also discuss the fact that isotropy of the temperature dependence of H(c2) straightforwardly follows from the Ginzburg-Landau theory if κ does not depend on the temperature.
authors.affiliation: Department of Chemistry and Biochemistry, University of Berne, Freiestrasse 3, CH-3012 Berne, Switzerland. Kapitza Institute for Physical Problems, 119334 Moscow, Russia.
authors.forename: I L
authors.initials: IL
authors.lastname: Landau