Triode-Sputtered High- T c Superconducting Thin Films

High- T c superconducting thin films were prepared by DC sputtering. Contrary to diode sputter methods, in the triode configuration applied here no compositional adjustment of the ceramic YBa 2 Cu 3 O x target appeared necessary. SrTiO 3 (100) was the best substrate found so far. After an onset at T co = 92 K, we found a complete superconductive transition at T cf = 86 K. At the transition a five-order decrease in resistivity could be measured. On other substrates such as Al 2 O 3 , MgO and ZrO 2 relatively poor results were obtained. Characterization was performed by SEM, x-ray diffraction and Rutherford backscattering (RBS).