Preparation by sol-gel, structure and superconductivity of pure and fluorinated LaBa2Cu3O7-d

Whereas an enormous amount of literature exists describing the preparation of the well known high T-c superconductor YBa2Cu3O7 as a single phase compo und with a transition temperature T-c similar to 92 K, very few reports hav e been published on the preparation of the rare earth analog compound LaBa2 Cu3O7. This report describes the preparation of LaBa2Cu3O7 compound by sol- gel technique. A single phase compound that showed an orthorhombicity of si milar to5 x 10(-3) and a T-c similar to 93 K was obtained. The fluorination of this compound did not alter the values of neither the lattice parameter s nor the T-c. (C) 2001 Elsevier Science B.V. All rights reserved.