Structural and magnetic properties of Li3RuO4

The crystal structure of Li3RuO4 has been refined from neutron powder diffraction data collected at 290 K (space group P2/a, a=5.1057(1), b=5.8545(1), c=5.1062(1) Angstrom, beta=110.039(1) degrees) and 5 K. It can be thought of as an ordered rock-salt structure with chains of edge-sharing RuO6 octahedra embedded in a matrix of LiO6 octahedra. Comparison of the structure with that predicted by computational chemistry shows that the calculations model well all but the Li sublattice. Consideration of Li-6 NMR spectra and the diffraction data shows that some (similar to1%) sites on the Li sublattice are occupied by Ru. SQUID magnetometry shows a non-hysteretic maximum in the magnetic susceptibility of Li3RuO4 at 50 K, but no long-range magnetic order is apparent at 5 K. The susceptibility maximum is therefore attributed to antiferromagnetic coupling within individual chains of RuO6 octahedra.