Microstructure of (001), (110) and (103) oriented thin films of YBa₂Cu₃O_7-x investigated with STM, SEM and HRTEM

Epitaxial films of (110) or (103) YBa2Cu3O7-x grown on (110) SrTiO3 substrates by laser ablation are compared to (001) films. Their microstructure is investigated with scanning tunneling microscopy, scanning electron microscopy and high-resolution transmission electron microscopy. The growth of steps, terraces and spirals originating from screw dislocations commonly seen in c-axis films is inhibited in films grown on (110) SrTiO3. In the case of (103) oriented films, the growth of 90° twisted domains produces a tooth-like structure with preferred orientation. The influence of vicinal substrates (a few degrees of misorientation) on the film growth, on the nature of defects and on the resistive behavior is also investigated. © 1994.