Abstract: The invention relates to a method of preparing thick films of YBa2Cu3O7-y(y=0.08) having a critical current density of the order of 106 A/cm2. The inventive method comprises using an inert carrier gas to send an aerosol, obtained from an aqueous solution of precursors of yttrium nitrate, barium nitrate and copper nitrate (0.11=FY=0.28, 0.46=FBa=0.58, 0.2=FCu=0.37), having a concentration which is essentially equal to the concentration at saturation, to the surface of a heated substrate whereon it undergoes pyrolysis for between 1 and 5 nm at 800° C. and 870° C., followed by oxygen annealing at a temperature which is greater than the pyrolysis temperature by at least 10° C. and between 850° C. and 880° C. for between 1 and 2 hours, and subsequently at 450° C.-550° C. for between 0.5 and 1.5 hours.