Search

The period rooms at Winterthur represent an almost century-long evolution from private residence to public decorative arts museum. Begun in the 1920s by Henry Francis du Pont, Winterthur opened to the public in 1951. Over the next half-century, the period rooms underwent a series of changes, guided first by du Pont and then professional curators. In the twenty-first century, the museum has focused on restoring many of du Pont’s original rooms to better reflect Winterthur’s history as the country residence of a wealthy gentleman while maintaining most to reflect the eighteenth- and nineteenth-century origins of their architecture and decorative arts.

Different precursor mixtures of 123 and 211 have been used to study the particle size distribution of the 211 phase. Melt texturing of these samples was performed by using a Sm-123 seed for preferential growth of single grain material and 211 substrates to soak the outflowing melt. The size distribution of the 211 inclusions was determined and their influence on the propagation of cracks in the textured material was studied. A precursor mixture of 15 wt% small grained 211 particles (1–5 μm) leads to the highest content of small sized 211 inclusions ( μ m). This material shows trapped magnetic fluxes up to 210 mT without any additional admixing.

Measurements of the thermal conductivity in the ab-plane of different YBa2Cu3O7-δ single crystals in the temperature range 2 K Tc, because separation of the electron thermal conductivity from the measured total value is complicated between these two limits. The results of analyzing some crystals provide a useful characterization of the mean densities of defects and show the dependence of the scattering mechanisms on the oxygen content. Es werden Messungen der Warmeleitfahigkeit in der ab-Ebene unterschiedlicher YBa2Cu3O7-δ Einkristalle im Temperaturbereich 2 K Tc verwendet, da die Separation des Elektronenanteils der Warmeleitfahigkeit zwischen diesen beiden Grenzen kompliziert ist. Die Ergebnisse einiger analysierter Kristalle bilden eine gute Charakterisierung bezuglich mittlerer Defektdichten und zeigen die Abhangigkeit der Streumechanismen vom Sauerstoffgehalt.

High-temperature superconducting samples of YBa2Cu3Ox with a defined oxygen stoichiometric amount have been prepared using a special equilibrium method. Results of structural investigations as well as thermal, electrical and magnetic measurements are discussed trying to understand the mechanism of the superconductivity and to make available standard values.