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YBaCuO films were grown on oxidized textured Ni sheets and on (100) and (110) oriented NiO single crystals by magnetron sputter deposition from a stoichiometric tubular target. The properties of the YBaCuO films are investigated as function of various preparation parameters (oxidation procedure of the sheets, substrate temperature T, , HTSC film thickness). At T, = 780 OC and for film thickness larger than 200 nm, the films have T, values around 80 K. The textures of the Ni sheets, NiO layers and YBaCuO films are determined using X-ray diffraction in Bragg-Brentano geometry and scanning electron microscopy. It is remarkable, that on textured oxidized Ni the YBaCuO films grow c-axis oriented. For comparison, the properties of films on differently oriented NiO single crystals are investigated. It is found that the film properties are better on (100) than on (110) surfaces.

Aus Lösungen von Sr(OH)2 in hochkonzentrierter heißer Natronlauge lassen sich bei langsamer Abkühlung Sr(OH)2‐Einkristalle geeigneter Größe erhalten. Die Kristallstruktur von Sr(OH)2, die bis auf die Wasserstoffatome nach den üblichen Röntgenbeugungsmethoden bestimmt wurde, stellt einen neuen Strukturtyp dar. Jedes Sr2+‐Ion ist von sieben OH−‐Ionen umgeben (mittlerer Abstand 2,60 Å). Die zugehörigen Koordinationspolyeder mit der idealisierten Symmetrie mm2 sind über gemeinsame Kanten in allen drei Raumrichtungen vernetzt. Die geometrische Anordnung der Polyeder weist eine bemerkenswerte Beziehung zur bekannten Kristallstruktur von YOOH auf.

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Biepitaxial Josephson Junctions were fabricated on MgO and SrTi03 (STO) suhstrates. ISlectriciil ch;ir;icteristics such as the critical current densities .Ic, contact resistivities Pn and IcRn-products on both sulwtrates are investigated. Junctions on MgO substrates are stable against thermal cycling in contrast to many junctions on STO sulx.trates. The obtained currentvoltage characteristics and Shapiro step oscillations are in agreement with the RSJ-model. The resistive transitions are strongly broadened. DC-SQUIDS patterned on both suhstriites show motluliitions tlV/tl~l, at 77 K. At 55 K the energy resolution E in the r;inge of white noise ties within a factor of two of the theoretical limit.