Synthesis, Crystal Structure, and Physical Properties of Sr0.93(SixNb1−x)Nb10O19 (x=0.87)

• Published in: Journal of solid state chemistry 2000-07, Vol.152 (2), p.540-545
• Main Authors: Tortelier, J., Emge, T.J., Veith, G., Greenblatt, M.
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Conductivity phenomena in semiconductors and insulators; Electronic transport in condensed matter; Exact sciences and technology; Inorganic compounds; Low-field transport and mobility; piezoresistance; Magnetic properties and materials; Magnetically ordered materials: other intrinsic properties; Physics; Saturation moments and magnetic susceptibilities; Structure of solids and liquids; crystallography; Structure of specific crystalline solids; Water, oxides, hydroxides, peroxides
• ISSN: 0022-4596; 1095-726X
• DOI: 10.1006/jssc.2000.8728

We present here the synthesis, crystal structure, and physical properties of a reduced niobium oxide Sr0.93(SixNb1−x)Nb10O19 (x=0.87). Its structure was determined on single crystal by X-ray diffraction in the space group R3 (ah=7.843(1), ch=42.26(2) Å, Vh=2251.3(9) Å3, and Z=6). The compound is isostructural to Na(SixNb1−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 μeff=3.16 μB/Nb, which is consistent with a 15-electron [Nb6O12] cluster, with Nb(IV) in the dimers and Nb(V) in the isolated NbO6 octahedra.