Crystal structure and ionic conductivity of ruthenium diphosphates, ARu2(P2O7)2 A = Li, Na, and Ag, were investigated. The structure of the Ag compound was determined by single crystal X-ray diffraction techniques. It crystallized in the triclinic space group P-1 with  a= 4.759Å, b = 6.843Å, c = 8.063Å, α = 90.44°, β = 92.80°, γ = 104.88°, V = 253.4Å3. Its host structure comprised of RuO6 and P2O7 groups and formed tunnels running along the a-axis, in which Ag+ ions were situated. The ionic conductivities were measured on pellets of the polycrystalline powders. The Li and Ag compounds exhibited the conductivities of 1.0 x 10-4 and 3.5 x 10-5S/cm at 150C, respectively. Magnetic susceptibility measurement of the Ag compound showed that it did not obey the Curie–Weiss law and the effective magnetic moment decreased as temperature decreased due to the large spin–orbital coupling effect of Ru4+ ions.

Crystal Structure and Ionic Conductivity of Ruthenium Diphosphate ARu2(P2O7)2, A = Li, Na, and Ag, with a Tunnel Structure. H.Fukuoka, H.Matsunaga, S.Yamanaka: Materials Research Bulletin, 2003, 38[6], 991-1001