Growth of Bicrystal Films of YBa₂Cu₃O₇ High-Temperature Superconductor, with CuO Planes Tilted by up to 90°, on SrTiO₃ Crystals

Bicrystal substrates, in which (100) planes in both single-crystal parts are rotated with respect to the surface by different angles around the [100] and [110] directions (parallel simultaneously to both the surface and bicrystal boundary), have been fabricated by solid-phase intergrowth on SrTiO₃ crystals. Epitaxial bicrystal YBa₂Cu₃O₇ films with different tilt angles of CuO planes to the surface have been grown on these bicrystals by pulsed laser deposition. The structure of these films has been investigated by X-ray diffraction. The films are shown to remain epitaxial when the film lattice is rotated from the position in which its (001) plane is oriented parallel to the surface by angles of up to 41° and 49° around the [100] and [110] axes, respectively. The possibility of growing bicrystal films of YBa₂Cu₃O₇ high-temperature superconductor (HTSC), in which the CuO planes at different sides of the bicrystal boundary make different angles (up to 90°, which is the maximum possible angle from the symmetry point of view), has been demonstrated based on these data.