Lithium Ruthenates: Controlling Dimensionality and Topology of Magnetic-Ion Arrangements

Abstract

In order to control the dimensionality and the topology of the arrangement of magnetic Ru ions, NaCl-type lithium ruthenates have been investigated. Three types of lithium ruthenates, Li\(_{3}\)RuO\(_{4}\), Li\(_{2}\)RuO\(_{3}\), and cubic-Li\(_{x}\)RuO\(_{1+x}\), were synthesized using a hydrothermal method. All of them have NaCl-type structure, but the arrangements of the cations, Li\(^{+}\) and Ru\(^{5+}\) (or Ru\(^{4+}\)), differ from each other. Li\(_{3}\)RuO\(_{4}\) with one-dimensional zigzag chains of Ru ions undergoes an antiferromagnetic transition at 66 K and exhibits an irreversibile magnetism below 32 K, where the zero-field-cooled susceptibility differs from the field-cooled susceptibility. Li\(_{2}\)RuO\(_{3}\) with a two-dimensional honeycomb network of Ru ions demonstrates a paramagnetism almost independent of temperature. A novel ruthenate cubic-Li\(_{x}\)RuO\(_{1+x}\), in which Ru and Li randomly occupy the cation sites of NaCl lattice, undergoes a spin-glass transition at 10 K.