PINNING FORCE DENSITY IN YBa₂Cu₃O₇-FILMS AND YBa₂Cu₃O₇/PrBa₂Cu₃O₇-SUPERLATTICES

Abstract

The in plane critical current density j c (B, Θ, T) of dc-sputtered YBa 2 Cu 3 O 7 -films and YBa 2 Cu 3 O 7 / PrBa 2 Cu 3 O 7 -superlattices was measured in dependence of the angle Θ between the magnetic field [Formula: see text] and the [Formula: see text]-axis of the films in two orientations: 1. The current direction is parallel to the axis of rotation (i.e. [Formula: see text] always). 2. The current flows perpendicular to the axis of rotation (i. e. [Formula: see text]). For low temperatures we do not find any difference between the two current orientations, and the critical current density [Formula: see text] behaves like j c (B cos Θ, 0°). For higher temperatures the two cases differ from each other for Θ near to the maxima in j c at 90° and 270° for the YBa 2 Cu 3 O 7 -films whereas for YBa 2 Cu 3 O 7 / PrBa 2 Cu 3 O 7 -superlattices we hardly find any change for both experimental setups. We compare the behaviour of the experimental results for the two orientations for the YBa 2 Cu 3 O 7 -films and YBa 2 Cu 3 O 7 / PrBa 2 Cu 3 O 7 -superlattices and discuss the temperature dependence of the intrinsic pinning force density.