Preparation and characterisation of single-phase Bi-Pb-Sr-Ca-Cu-O high temperature superconductors

✍ Scribed by N. Knauf; J. Harnischmacher; R. Müller; R. Borowski; B. Roden; D. Wohlleben

• Publisher: Elsevier Science
• Year: 1991
• Tongue: English
• Weight: 930 KB
• Volume: 173
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(91)90744-j

✦ Synopsis

We identify the preparation procedures to obtain polycrystalline pellets of Bi-22 12 and of Bi-2223 high-temperature superconductors, which show only the superconducting properties and the X-ray diffraction pattern of one or the other phase ("singlephase" pellets). These procedures were found by systematic variation of the preparation, with substitution of PbO for BiZO, as well as with addition of PbO to the stoichiometric mixture of starting powders. Bi-2223 in single-phase form has a r, of 107.5 f 0.5 K, whereas single-phase pellets of "Bi-2212" can have sharp transitions with TZR's between 55-95 K, depending on the oxygen partial pressure of the atmosphere in the final annealing step.