1. Institut für Anorganische Chemie der Universit?t, Auf der Morgenstelle 18, D-72076, Tübingen, Germany 2. Hahn-Meitner-Institut Berlin GmbH, Glienicker Strasse 100, D-14109, Berlin, Germany
Abstract:
In the system Bi-0212 the carrier concentration can be changed by both cation substitution and oxygen content. The crystal
structure of Ca substituted material was refined from neutron powder diffraction data for Bi0.5Sr1.5Ca0.5Y0.5Cu1.5Fe0.5Oy. It is shown that extra oxygen is introduced in the cation layers between the double sheets of Cu/O pyramids. In superconducting
material the familar dependence ofTc on the hole carrier concentration is observed. The higherTc is situated at 75 K.