Preparation of superconducting YBa2Cu3O7-delta nanopowder by deoxydation in Ar before final oxygenation

: Raittila J, Huhtinen H, Paturi P, Stepanov YP

Publisher: ELSEVIER SCIENCE BV

: 2002

Physica C: Superconductivity and its Applications

PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS

: PHYSICA C

: 371

: 2

: 90

: 96

: 7

: 0921-4534

DOI: https://doi.org/10.1016/S0921-4534(01)01059-0

Superconducting YBa2Cu3O7-delta nanopowder is prepared by the citrate-gel modification of the sol-gel method. Most important advantages of this method are the homogeneity at atomic level and possibility to reduce the calcination temperature to limit thermal agglomeration of the particles. A preparation temperature less than or equal to800 degreesC is used with a deoxydation step in Ar before the final oxidation. The X-ray diffraction data confirm the orthorhombic structure of the nanopowder. Superconducting properties are investigated with a SQUID magnetometer showing that the global T-c = 92 K. Single grains of the powder have average diameter of 60-80 nm, depending on the calcination process used. The grains are weakly connected stacks of flat particles having thickness of a few nanometer. (C) 2001 Elsevier Science B.V. All rights reserved.