Triode-sputtered high-T_csuperconducting thin films

High-T_csuperconducting thin films were prepared by DC sputtering. Contrary to diode sputter methods, in the triode configuration applied here no compositional adjustment of the ceramic YBa₂Cu₃O_xtarget appeared necessary. SrTiO₃(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 Al₂O₃, MgO and ZrO₂relatively poor results were obtained. Characterization was performed by SEM, x-ray diffraction and Rutherford backscattering (RBS).