Vanadium(IV) oxide
From Wikipedia, the free encyclopedia
| Vanadium(IV) oxide | |
|---|---|
| Image:Vanadium(IV) oxide.jpg | |
| General | |
| Systematic name | ? |
| Other names | ? |
| Molecular formula | VO2, or V2O4 |
| SMILES | ? |
| Molar mass | 165.88 g/mol (V2O4) |
| Appearance | ? |
| CAS number | [12036-21-4] |
| Properties | |
| Density and phase | ? g/cm3, ? |
| Solubility in water | ? g/100 ml (?°C) |
| Melting point | ?°C (? K) |
| Boiling point | ?°C (? K) |
| Acidity (pKa) | ? |
| Basicity (pKb) | ? |
| Chiral rotation [α]D | ?° |
| Viscosity | ? cP at ?°C |
| Structure | |
| Molecular shape | ? |
| Coordination geometry |
? |
| Crystal structure | ? |
| Dipole moment | ? D |
| Hazards | |
| MSDS | External MSDS |
| Main hazards | ? |
| NFPA 704 | |
| Flash point | ?°C |
| R/S statement | R: ? S: ? |
| RTECS number | ? |
| Supplementary data page | |
| Structure and properties |
n, εr, etc. |
| Thermodynamic data |
Phase behaviour Solid, liquid, gas |
| Spectral data | UV, IR, NMR, MS |
| Related compounds | |
| Other anions | ? |
| Other cations | ? |
| Related ? | ? |
| Related compounds | ? |
| Except where noted otherwise, data are given for materials in their standard state (at 25°C, 100 kPa) Infobox disclaimer and references |
|
Vanadium(IV) oxide is a solid
Chemical symbol: VO2. Intermediate formed in the contact process from V2O5, which acts as a catalyst.
Vanadium more commonly exists in the form of vanadium(V) oxide. However, vanadium is a transition metal and is able to form variable oxidation states. See the main vanadium article for further information.
Tungsten-doped vanadium dioxide (W:VO2) with 1.9% tungsten content has been investigated for use as a "spectrally-selective" window coating to block infrared transmission and reduce the loss of building interior heat through windows. This material behaves like a semiconductor at temperatures below 29 °C, allowing more transmission, and like a conductor at higher temperatures, providing much greater reflectivity. [1] [2] Varying the amount of tungsten allows regulating the phase transition temperature. However, the coating has a slight yellow-green color. [3]
Vanadium dioxide can act as an extremely fast optical shutter. The thermochromic phase transition between the transparent semiconductive and reflective conductive phase, occurring at 68 °C, can happen in times as short as a one tenth of a trillionth of a second. [4]
Vanadium dioxide, especially in its nanocrystalline form, may find use in glazing applications, extremely fast optical shutters, optical modulators, infrared modulators for missile guidance systems, cameras, data storage, and other applications.
[edit] External links
 |
This inorganic compound-related article is a stub. You can help Wikipedia by expanding it. |
