Semiconducting epitaxial films of metastable SrRu_0.5Sn_0.5O₃ grown by pulsed laser deposition

Synthesis of the perovskite solid solution that forms between metallic SrRuO3 and insulating SrSnO3 is reported. This material is proposed as a conducting thin-film electrode/epitaxial-substrate material. While the bulk solid solution could not be formed, thin films of single-phase SrRu0.5Sn0.5O3 were grown on (001) KTaO3 single-crystal substrates by pulsed laser deposition. These films exhibit a commensurate in-plane lattice match with KTaO3 (α = 3.989 Å); accordingly, the lattice constant of SrRu0.5Sn0.5O3 is larger than that of commonly used conducting-oxide thin-film electrodes (e.g., SrRuO3, LaNiO3, and YBa2Cu3O7-δ). The SrRu0.5Sn0.5O3 films were analyzed using x-ray diffraction, Rutherford backscattering, atomic force microscopy, Z-contrast transmission electron microscopy, and Hall effect measurements. The results revealed excellent atomic-scale structural properties, flat surfaces (13 Å rms roughness), and p-type conduction with a room-temperature resistivity of 16 mΩ cm. © 1997 American Institute of Physics.