Lithium-MVO[sub 5] (M = Nb, Ta) bronzes

Journal Article · · Chemistry of Materials; (United States)

OSTI ID:6458488

Amarilla, J M; Casal, B; Galvan, J C; Ruiz-Hitzky, E ^[1]

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1. Instituto de Ciencia de Materiales de Madrid (Spain)

Mixed oxides NbVO[sub 5] and TaVO[sub 5] have been synthesized by a sol-gel procedure. Both compounds are isostructural with the so-called [open quotes]monophosphate tungsten bronzes[close quotes] (MPTB, (PO[sub 2])[sub 4](WO[sub 3])[sub 2m], with m = 2). In such structures single MO[sub 4] tetrahedra (M = P, V), share corners with M'O[sub 6] octahedra (M' = W, Ta, Nb) building pentagonal tunnels along the [010] direction. In this work, the authors have studied lithium insertion redox reactions carried out by treatments with LiI in acetonitrile in MVO[sub 5] (M = Nb, Ta) hosts. Lithium insertion appears as a topotactic and reversible process. The intercalated compounds constitute a new family of Li bronzes showing Li[sub x]MVO[sub 5] compositions with 0 [le] x [le] 0.3, which have been characterized by X-ray diffraction, conventional chemical analysis, and X-ray photoelectron spectroscopy. Complex impedance spectroscopy reveals the ionic character of the electrical conductivity in Li[sub x]MVO[sub 5]. Typical values of the specific conductivity are in the 10[sup [minus]6]10[sup [minus]8][Omega][sup [minus]1] cm[sup [minus]1] range at 573 K, with activation energies on the order of 0.5 eV. 24 refs., 7 figs., 4 tabs.

• OSTI ID: 6458488
• Journal Information: Chemistry of Materials; (United States), Journal Name: Chemistry of Materials; (United States) Vol. 4:1; ISSN CMATEX; ISSN 0897-4756
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202 -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
ACTIVATION ENERGY
ALKALI METAL COMPOUNDS
CHALCOGENIDES
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTRON SPECTROSCOPY
ENERGY
LITHIUM COMPOUNDS
LITHIUM OXIDES
NIOBIUM COMPOUNDS
NIOBIUM OXIDES
OXIDES
OXYGEN COMPOUNDS
PHOTOELECTRON SPECTROSCOPY
PHYSICAL PROPERTIES
REFRACTORY METAL COMPOUNDS
SOL-GEL PROCESS
SPECTROSCOPY
STRUCTURAL CHEMICAL ANALYSIS
TANTALUM COMPOUNDS
TANTALUM OXIDES
TRANSITION ELEMENT COMPOUNDS
VANADIUM COMPOUNDS
VANADIUM OXIDES
X-RAY SPECTROSCOPY