Abstract. Composite structures such as High-Tc multi-filamentary tapes display a complex anisotropy arising from the combination of the "intrinsic" anisotropy of the Bi-2223 grains, and that associated to the superconducting phase distribution in the superconductor-metal composite, as well as cracks and other defects. In this paper we characterize the "in-plane" anisotropy of BSCCO-Ag tapes, i.e., the difference between the transport properties along the longitudinal axis and those along the transverse direction also lying on the wide face of the tape. In particular, we demonstrate that the dissipation associated to transport along the transverse direction approaches that of the longitudinal direction as the temperature or the current increase, which may be relevant to transport applications in situations where the superconducting properties have significantly degraded.PACS numbers: 84.71. Mn, 74.25.Sv

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The electrical properties of superconducting tapes and coatings in the direction transverse to the long dimension of the composite has been rarely studied. However, transverse dissipation can eventually determine the behavior of a transmission line in the case of failure due to the presence of transversal cracks, and is also fundamental in the AC regime. In this paper we present a preliminary experimental study of the electrical transport properties along the transverse direction of BSCCOmetal tapes, and compare them with those measured along the long axis of the material. In spite of the fact that the tapes under study are not multi-filamentary, our experiments suggest that there is a measurable anisotropy of the transport properties between the longitudinal and transverse directions.

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An inhomogeneity into a conductive matrix deforms the flow pattern of an applied electric current. A usual current cloak can be defined as a permanent modification of the matrix properties around the inhomogeneity guaranteeing that the current flow pattern is similar before and after passing by the modified zone, so it implies the ‘electrical invisibility’ of the inhomogeneous region. Here we introduce the concept of a current cloak that can be tuned by means on an external field. We demonstrate analytically and using finite elements simulations that a current cloak can be constructed and manipulated by an external magnetic field for a concrete system consisting in a magneto-resistive matrix with an inclusion of larger conductivity.