Pre-product and method for producing a strip-like high-temperature superconductor

Abstract

The present invention relates to a precursor () for production of a high-temperature superconductor (HTS) in ribbon form, comprising a metallic substrate () in ribbon form having a first ribbon side () and a second ribbon side (), wherein, on the first ribbon side (), (a) the substrate () has a defined texture as template for crystallographically aligned growth of a buffer layer or an HTS layer and (b) an exposed surface of the substrate () is present or one or more layers () are present that are selected from the group consisting of: buffer precursor layer, pyrolyzed buffer precursor layer, buffer layer, HTS precursor layer, pyrolyzed HTS buffer precursor layer and pyrolyzed and further consolidated HTS buffer precursor layer, and, on the second ribbon side (), at least one ceramic barrier layer () that protects the substrate () against oxidation or a precursor which is converted to such a layer during the HTS crystallization annealing or the pyrolysis is present, wherein, when one or more layers () are present on the first ribbon side (), the ceramic barrier layer () or the precursor thereof has a different chemical composition and/or a different texture than the layer () arranged on the first ribbon side () and directly adjoining the substrate (). In this precursor, the barrier layer () is a layer that delays or prevents ingress of oxygen to the second ribbon side () and is composed of conductive ceramic material or a precursor which is converted to such a precursor during the HTS crystallization annealing or the pyrolysis, and the ceramic material is an electrically conductive metal oxide or an electrically conductive mixture of metal oxides, wherein the conductive metal oxide or one or more metal oxides in the conductive mixture is/are preferably metal oxide(s) doped with an extraneous metal.