The Role of Nonlocality in the Pinning Properties of Borocarbides Materials
Loading...
Date
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Description
An experimental review on the influence of nonlocal electrodynamics in the vortex pinning properties of non-magnetic borocarbide superconductors is presented. We show that the pinning force density Fp exhibits a rich and complex anisotropic behavior that sharply contrast with the small mass anisotropy of these compounds. For magnetic fields H applied parallel to the crystallographic c-axis, the first order reorientation transition between two rhombic lattices manifests itself as a kink in Fp(H). For H perpendicular to the c-axis, a much larger Fp(H) and a slower relaxation rate is observed. In this field configuration, nonlocality induces a fourfold periodicity in Fp when H is rotated within the square basal plane. Unlike the out-of-plane anisotropy, which persists for increasing impurity levels, the in-plane fourfold anisotropy can be strongly suppressed by reducing the electronic mean free path. This result unambiguously demonstrate that the in-plane anisotropy is a consequence of nonlocal effects.
19 pages, 9 figures, to be published in Horizons in Superconductivity Research, edited by Frank Colombus, Nova Science Publishers, New York (2003)
19 pages, 9 figures, to be published in Horizons in Superconductivity Research, edited by Frank Colombus, Nova Science Publishers, New York (2003)