New superconductors stage 1: preparation, characterization and physical investigation of HTC superconductors. (YBa2Cu3O7-x), development of thin films and new systems. Final report

The first aim of the project was, to produce and characterize high temperature superconductors (HTSC) as well as materials with a similar electronic structure in the form of ceramics, thin films and single crystals. New production routes such as chemical precipation were explored. In parallel at the company Villeroy and Boch established methods for the production and processing of ceramic materials were explored for their application to the use in HTSC materials production. An analytical chemical laboratory for the characterization of HTSC materials was established. Secondly, with the methods of physical chemistry, the defect chemistry of the HTSC was investigated at the reaction temperatures. A model to describe the reversible incorporation of the oxygen into the YBCO was developed. Finally, the different methods of electron spectroscopy yield the important results, that the electronic structure of the HTSC can be described by strongly correlated copper-oxygen-hybrides. At Tc no crystallographically visible structural phase transition could be detected. With theoretical methods, the melting process of the fluxoid lattice was investigated. (orig.)