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

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 $BaRuO3.$