Laser deposition of Y1Ba2Cu3O7-delta-SrTiO3-Y1Ba2Cu3O7-delta multilayers utilizing the 4th harmonics of Nd:YAG pulse laser

The 4th harmonics of a Nd:YAG laser beam (266 nm) is applied to fabricate highly oriented Y1Ba2Cu3 O-7-delta-SrTiO3-Y1Ba2Cu3O7-delta multilayer structures. It has been shown that the emission temperature of a film surface will change during deposition, depending on deposition conditions, even though the hearer temperature is constant. The change of substrate temperature is strongly correlated to film characteristics such as critical temperature, c-axis length, and resistivity. The in situ monitoring of the Substrate temperature is useful for obtaining high-quality Y1Ba2Cu3O7-delta films reproducibly. It is also shown that a SrTiO3 layer prevents oxygen restoration in a Y1Ba2Cu3O7-delta underlayer. The relationship between oxygen deficiency and the annealing conditions is studied.