VNb{sub 9}O{sub 25-{delta}}-Synthesis, electrical conducting behaviour and density functional theory (DFT) calculation

Journal Article · Sat Aug 15 00:00:00 EDT 2009 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2009.05.015· OSTI ID:21370520

Bergner, Carina; Vashook, Vladimir ^[1]; Leoni, Stefano ^[2]; Langbein, Hubert ^[1]

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1. Fachrichtung Chemie und Lebensmittelchemie, Technische Universitaet Dresden, Helmholtz Str. 10, D-01069 Dresden (Germany)
2. Max-Planck-Institut fuer Chemische Physik fester Stoffe, Noethnitzer Str. 40, D-01187 Dresden (Germany)

In order to investigate the influence of the oxygen partial pressure (p(O{sub 2})) on the electrical conductivity, VNb{sub 9}O{sub 25} was prepared by thermal decomposition of freeze-dried oxalate precursors and by a solid state reaction of V{sub 2}O{sub 5}/Nb{sub 2}O{sub 5} mixtures. The samples were characterised by X-ray diffraction, grain size analysis and scanning electron microscopy (SEM). The electrical conductivity of the n-type semiconductor VNb{sub 9}O{sub 25-{delta}} can be interpreted as an activated hopping process with a preferred localisation of charge carriers at V(IV) centres. The electronic structure of VNb{sub 9}O{sub 25-{delta}} was calculated within the framework of the local density approximation (LDA) to DFT. Partial reduction of V(V) centres causes localised vanadium states to appear inside the band gap. The calculated activation energy values are in good agreement with the experimental ones. - Graphical Abstract: The electrical conductivity of the n-type semiconductor VNb{sub 9}O{sub 25-{delta}} can be interpreted as an activated hopping process with a preferred localisation of charge carriers at V(IV) centres. The electronic structure of VNb{sub 9}O{sub 25-{delta}} was calculated within the framework of the local density approximation (LDA) to DFT. The partial reduction of V(V) centres causes localised vanadium states to appear inside the band gap.

• OSTI ID: 21370520
• Journal Information: Journal of Solid State Chemistry, Vol. 182, Issue 8; Other Information: DOI: 10.1016/j.jssc.2009.05.015; PII: S0022-4596(09)00204-7; Copyright (c) 2009 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ACTIVATION ENERGY
CHARGE CARRIERS
DENSITY FUNCTIONAL METHOD
ELECTRIC CONDUCTIVITY
ELECTRONIC STRUCTURE
NIOBIUM OXIDES
OXYGEN
PARTIAL PRESSURE
PYROLYSIS
REDUCTION
SCANNING ELECTRON MICROSCOPY
SEMICONDUCTOR MATERIALS
SYNTHESIS
VANADIUM OXIDES
X-RAY DIFFRACTION
CALCULATION METHODS
CHALCOGENIDES
CHEMICAL REACTIONS
COHERENT SCATTERING
DECOMPOSITION
DIFFRACTION
ELECTRICAL PROPERTIES
ELECTRON MICROSCOPY
ELEMENTS
ENERGY
MATERIALS
MICROSCOPY
NIOBIUM COMPOUNDS
NONMETALS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
REFRACTORY METAL COMPOUNDS
SCATTERING
THERMOCHEMICAL PROCESSES
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
VANADIUM COMPOUNDS
VARIATIONAL METHODS