Thin YBa2Cu3O7−δ films by electron-beam coevaporation— Growth and in situ characterization

We report on the in situ preparation and characterization of thin YBa2Cu3O7−δ films on various substrates. The films were grown by electron-beam coevaporation of the pure metals Y, Ba, and Cu. A pressure stage is used to obtain high partial O2 pressure close to the substrate and low pressure in the main vacuum system. In situ resistance measurements were performed to investigate growth dynamics during film formation, and temperature dependence during the cool down from T≊1000 K to T≤Tc. The films were analyzed by R(T), ac susceptibility, x-ray diffraction, and critical transport current measurements.