Epitaxial growth of BaRuO₃ thin films on MgO substrates by laser ablation

Epitaxial BaRuO₃ (BRO) thin films were prepared on (001) and (111) MgO substrates by laser ablation, and the relationship of lattice matching, morphology and electrical conductivity was investigated. (205)- and (001)-oriented rhombohedral BRO thin films were epitaxially grown on (001) and (111) MgO substrates, respectively. The (205) BRO thin films showed an orthogonal texture with faceted island grains, whereas the (001) BRO thin films had a hexagonal columnar structure with a flat terrace. Epitaxial BRO thin films showed metallic conduction, and the (205) BRO thin films exhibited the highest electrical conductivity, i.e., 1.0 × 105 S.m^-1, at room temperature. A higher lattice matching between epitaxial thin film and the substrate yielded a higher electrical conductivity.