Growth of high T_c superconducting thin films using molecular beam epitaxy techniques

Thin films of the high‐temperature superconductor DyBa₂Cu₃O_7−x have been grown on SrTiO₃ substrates using molecular beam epitaxy techniques. Reflection high‐energy electron diffraction patterns observed during deposition indicate incomplete oxidation of copper and growth of oriented metallic copper microcrystals in a matrix of amorphous barium and dysprosium oxides. After post‐growth anneal the films exhibited sharp superconducting transitions with zero resistance observed as high as 89 K and critical current densities of 4.8×10⁵ A/cm² at 4.2 K and 3.9×10⁴ A/cm² at 77 K.