Deposition and characterization of thin HTS and magnetic perovskite films

The in-situ growth and physical properties were investigated of thin films and bilayers of high-temperature superconductors (HTS) YBa2Cu3O7 (YBCO) and ferromagnetic (FM) manganites La0.7Sr0.3MnO3 (LSMO) and La0.7Ca0.3MnO3 (LCMO) with thicknesses of several tens of nm obtained by magnetron sputtering. Similar twin structures were observed by an optical microscope in areas on the LaAlO3 substrate surface void of films, in areas containing YBCO, in LSMO films, and in YBCO/LCMO bilayers, although the main spatial period of the twin structure seemed to be slightly different in the areas containing the LSMO film. The resistance (and its temperature dependence) of the LCMO films strongly depends on the annealing conditions. The resistance of the LSMO and LCMO films grown on Al2O3 substrates decreased as the temperature (T) was increased in the lower and higher temperature ranges, and increased as T was increased at medium temperatures.