We present here the synthesis, crystal structure, and physical properties of a reduced niobium oxide Sr0.93(Si(x)Nb(1-x))Nb10O19 (x = 0.87). Its structure was determined on single crystal by X-ray diffraction in the space group R3̄ (a(h) = 7.843(1), C(h) = 42.26(2) Å, V(h) = 2251.3(9) Å3, and Z = 6). The compound is isostructural to Na(Si(x)Nb(1-x)) Nb10O19 (x ≃ 0.75) and exhibits discrete [Nb6O12] clusters, Nb2O10 dimers, NbO6 octahedra, SrO12 cubo-octahedra, and SiO4 tetrahedra. The compound is insulating with a room-temperature resistivity ˜50 Ω cm. The magnetic susceptibility data yields μ(eff) = 3.16 μ(B)/Nb, which is consistent with a 15-electron [Nb6O12] cluster, with Nb(IV) in the dimers and Nb(V) in the isolated NbO6 octahedra. (C) 2000 Academic Press.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Condensed Matter Physics
- Physical and Theoretical Chemistry
- Inorganic Chemistry
- Materials Chemistry