Bulk YBCO samples have been prepared for the first time by using Metal-Organic Deposition (MOD) technique.
Solutions of Y, Ba and Cu neodecanoates have been used in order to obtain directly YBCO powders (not exactly, but approximately stoichiometric) after a back-up and a pyrolysis step at 500°C. The powders have been successively pressed and subjected to two annealing steps in order to built up the YBCO structure, to increase grain dimensions and to adjust oxygen stoichiometry. The samples, which are disk-shaped, 1 mm thick and 1 cm wide, display a sharp superconducting transition at 93 K and possess a relatively large critical current.
Diffraction patterns indicate a strong degree of orientation of (a,b) planes along the surface. The superconducting gap has been measured by SIS' tunneling with Nb and by investigation on SS' Andreev reflection.