The effect of substrate temperature on the epitaxial growth of superconducting YBa2Cu3O6,9 films under laser evaporation

An intermediate-power (approx-lt 0.05 J/pulse) laser two orders of magnitude lower than the customary power level, was used to evaporate epitaxial single-crystal YBa2Cu3O6,9 films on the (100) plane of a SrTiO3 substrate. Experimental studies of the electrical resistivity and x-ray diffraction have been carried out to determine the effect of the temperature rerime on the epitaxial growth of films under these conditions. The Auger spectra of the films have been analyzed for the first time without the application of destructive purification methods. The films with Tc=88.5 K, ΔT∼1 K, and Icr=<5x105 A/cm2, obtained at the substrate temperature of 900 degree C are found to have a stoichiometric composition at 77 K. No film degradation has been observed after a two-month exposure to air