YBaCo4O7+Â powders were obtained by standard solid state reaction und their structural and morphological properties carefully analyzed. The X-ray powder diffraction patterns showed reflexes corresponding to a pure hexagonal structure (space group P63mc). The lattice parameters resulted to be very close to those reported in the literature (a=6.3065 A, c=10.2558 A) for high-quality samples. The EDS analysis confirms that the cationic composition YBaCo3.97Ox is in agreement with the nominal one in the limit of experimental errors. The great affinity of YBaCo4O7+Â for oxygen has been firmly established by several research groups [1-3] who demostred the large oxidation- reduction capabilities of material at temperatures near 350 C. As much as 1-~1.5 extra oxygen atoms perunit formula have successfully been added to the material at ambient and high oxygen pressures, respectively. The type compound itself (YBaCo4O7+Â) has already been considered for applications as oxygen storage material, oxygen membrane, and cathode material.