Electrical and magnetic properties of a series of ternary barium metal ruthenates:Ba3MRu2O9(M=Fe,Co, Ni, Cu, and In)

Abstract

The resistivities and magnetic susceptibilities of the ${\mathrm{Ba}}_{3}M{\mathrm{Ru}}_{2}{\mathrm{O}}_{9}$ series of compounds, with $M=\mathrm{Fe},$ Co, Ni, Cu, and In, are reported. All compounds have regular or distorted versions of the hexagonal barium titanate structure, consisting of chains of face-sharing ${\mathrm{RuO}}_{6}$ octahedra interconnected by corner-sharing $M{\mathrm{O}}_{6}$ octahedra. The compounds are semiconductors with $\ensuremath{\rho}>0.1\ensuremath{\Omega}\mathrm{cm}$ at ambient temperature. The magnetic susceptibilities below 400 K show that the $3d$ elements display local moments, and that the variants with $M=\mathrm{Co},$ Ni, and Cu have magnetic transitions near 100 K.