Preparation by sol-gel, structure and superconductivity of pure and fluorinated LaBa₂Cu₃O_7-d

Whereas an enormous amount of literature exists describing the preparation of the well known high T_c superconductor YBa₂Cu₃O₇ as a single phase compound with a transition temperature T_c ∼ 92 K, very few reports have been published on the preparation of the rare earth analog compound LaBa₂Cu₃O₇. This report describes the preparation of LaBa₂Cu₃O₇ compound by sol-gel technique. A single phase compound that showed an orthorhombicity of ∼5 × 10^-3 and a T_c ∼ 93 K was obtained. The fluorination of this compound did not alter the values of neither the lattice parameters nor the T_c.