Superconductivity in (${\mathrm{La}}_{0.9}$${\mathrm{Sr}}_{0.1}$${)}_2$${\mathrm{CuO}}_4$ single-crystal films

Single-cyrstal thin films of layered tetragonal-structure (${\mathrm{La}}_{0.9}$ ${\mathrm{Sr}}_{0.1}$ ${)}_2$ ${\mathrm{CuO}}_4$ have been grown epitaxially on a (100) ${\mathrm{SrTiO}}_3$ substrate by a sputtering technique. The basal plane of the tetragonal structure was parallel to the surface of the substrate. The films showed superconductivity after postannealing. The onset temperature was 34 K with a transition width of 3 K. These properties are similar to those of the single-phase La-Sr-Cu-O ceramics.