Lattice deformation and magnetic properties in epitaxial thin films of Sr1−xBaxRuO3

Abstract

Crystal structure and magnetic properties in epitaxially grown Sr1−xBaxRuO3 on SrTiO3 substrates were determined. Epitaxial Sr1−xBaxRuO3 exhibits a simple perovskite structure in the whole region of the Ba/Sr ratio, in contrast to the complex hexagonal layered perovskite of Ba-rich bulk Sr1−xBaxRuO3, which has plane-sharing oxygen octahedra. Tetragonal deformation was enhanced from pseudocubic in SrRuO3 to a highly distorted tetragonal lattice in BaRuO3. Electronic properties such as conductivity and magnetization were examined. A metal–insulator transition was not observed in this system, and metallic conductivity was maintained in the whole region of Ba concentration. Ferromagnetic ordering at 160 K seen in bulk SrRuO3 was observed to be suppressed in the Sr1−xBaxRuO3 films with increasing tetragonal deformation and Curie temperatures decreased to 50 K in BaRuO3.