NEW TECHNIQUE FOR THE DEPOSITION OF HIGH Tc SUPERCONDUCTING FILMS

Thin films of YBa2Cu3O7-x superconductors have been prepared using a new deposition technique based on the pyrolysis of an ultrasonic generated aerosol containing the Y-Ba-Cu precursors. This technique leads to a very good quality of the film surface and allows to control accurately the film thickness. Films of about 0.2 to 6 µm in thickness have been annealed in air at 500°C, heated under oxygen at temperatures ranging from 900 to 960°C and then slowly cooled in oxygen to room temperature. This method leads to well crystallized YBa2Cu3O7-x films with a good grain size homogeneity and a texture in the 001 direction depending on the heat treatment conditions. SrTiO3, YSZ or MgO single crystals and ceramics have been used as substrates. In this paper we discuss the influence of the experimental conditions on the microstructure, morphology and superconducting properties of the films.