Wikipedia
Vanadium(V) oxide (vanadia) is the inorganic compound with the formula VO. Commonly known as vanadium pentoxide, it is a brown/yellow solid, although when freshly precipitated from aqueous solution, its colour is deep orange. Because of its high oxidation state, it is both an amphoteric oxide and an oxidizing agent. From the industrial perspective, it is the most important compound of vanadium, being principal precursor to alloys of vanadium and is a widely used industrial catalyst.
The mineral form of this compound, shcherbinaite, is extremely rare, almost always found among fumaroles. A mineral trihydrate, VO·3HO, is also known under the name of navajoite.
Vanadium(IV) dioxide is an inorganic compound with the formula VO. It is a dark blue solid. Vanadium(IV) dioxide is amphoteric, dissolving in non-oxidising acids to give the blue vanadyl ion, [VO] and in alkali to give the brown [VO] ion, or at high pH [VO]. VO has a phase transition very close to room temperature(~66 °C). Electrical resistivity, opacity, etc, can change up several orders. Due to these properties, it has been widely used in surface coating, sensors, and imaging. Potential applications include use in memory devices.
Vanadium(III) oxide is the inorganic compound with the formula VO. It is a black solid prepared by reduction of VO with hydrogen or carbon monoxide.It is a basic oxide dissolving in acids to give solutions of vanadium(III) complexes. VO has the corundum structure. It is antiferromagnetic with a critical temperature of 160 K. At this temperature there is an abrupt change in conductivity from metallic to insulating.
Upon exposure to air it gradually converts into indigo-blue VO.
In nature it occurs as the rare mineral karelianite.
Vanadium(II) oxide, VO, is one of the many oxides of vanadium. VO is a long-lived, electronically neutral reagent chemical. It adopts a distorted NaCl structure and contains weak V-V metal to metal bonds. As shown by band theory, VO is a conductor of electricity due to its partially filled conduction band and delocalisation of electrons in the t orbitals. VO is a non-stoichiometric compound, its composition varying from VO to VO.
Vanadium oxide may refer to:
- Vanadium(II) oxide (vanadium monoxide), VO
- Vanadium(III) oxide (vanadium sesquioxide or trioxide), VO
- Vanadium(IV) oxide (vanadium dioxide), VO
- Vanadium(V) oxide (vanadium pentoxide), VO
In addition to these principal oxides of vanadium, various other distinct phases exist:
- Phases with the general formula VO exist between VO and VO. Examples of these phases include VO, VO and VO.
- Phases with the general formula VO exist between VO and VO. Called Magnéli phases for Arne Magnéli, they are examples of crystallographic shear compounds based on the rutile structure. Examples of Magnéli phases include VO, VO, VO, VO and VO.
Many vanadium-oxygen phases are non-stoichiometric.