Chemical incorporation of fluorine into YBa2 Cu3O6.5+δ

Abstract Evidence of incorporation of fluorine into the lattice of 1,2,3,7 orthorhombic superconducting oxide by a reaction of this compound with NH 4 HF 2 at 600K is presented. While TG/DTA data give clue to the reaction between the two, XRD of the product shows a broad peak around 2 Θ =26° which disappears on heating to 1000K giving BaF 2 peaks. The product with four F atoms in place of two O atoms shows T c close to that in the virgin orthorhombic oxide.