Direct laser writing of superconducting patterns of Y₁Ba ₂Cu₃O_7-δ

Direct argon ion laser writing of 40-μm-wide and 3-μm-thick superconducting lines of Y1Ba2Cu3O 7-δ on magnesium oxide (MgO) substrate is reported. A 514.5 nm laser beam of 300 mW was focused onto a thin sprayed film of the nitrate precursors (Y:Ba=1:2:3) and scanned over it. The laser beam converted oxides along the irradiation path. The film was then "developed" by rinsing it in ethanol, which removed the unirradiated areas, but left the irradiated areas intact. This was followed by the standard oven annealing procedure in flowing oxygen. The resistivity of the laser-written lines as a function of temperature showed an onset and completion of the superconducting transition at 82 and 69 K, respectively. The corresponding values of the unpatterned, blanket film were 82 and 77 K, respectively.