Everything about The Drude Model totally explained
The
Drude model of
electrical conduction was developed in the
1900s by
Paul Drude to explain the transport properties of
electrons in materials (especially metals). The Drude model is the application of
kinetic theory to electrons in a solid. It assumes that the material contains immobile positive ions and an "electron gas" of classical, non-interacting electrons of density
n, each of whose motion is damped by a frictional force due to collisions of the electrons with the ions, characterized by a relaxation time
τ.
Explanation
The Drude model assumes that an average charge carrier experiences a `drag-coefficient'
. Under an applied
electric field E this leads to the following
differential equation:
»
In other conventions,
is replaced by
in all equations. The imaginary part indicates that the current lags behind the electrical field, which happens because the electrons need roughly a time
to accelerate in response to a change in the electrical field. Here the Drude model is applied to electrons; it can be applied both to electrons and holes; for example, positive charge carriers in semiconductors.
Inadequacies of model
This simple classical model provides a very good explanation of DC and AC conductivity in
metals, the
Hall effect, and
thermal conductivity (due to electrons) in metals, although it greatly overestimates the electronic heat capacities of metals. In reality, metals and insulators have roughly the same heat capacity at room temperature. Also, the Drude model fails to explain the existence of apparently positive charge carriers as demonstrated by the Hall effect.
Further Information
Get more info on 'Drude Model'.
|
External Link Exchanges
Do you know how hard it is to get a link from a large encyclopaedia? Well we're different and will prove it. To get a link from us just add the following HTML to your site on a relevant page:
<a href="http://drude_model.totallyexplained.com">Drude model Totally Explained</a>
Then simply click through this link from your web page. Our crawlers will verify your link, extract the title of your web page and instantly add a link back to it. If you like you can remove the words Totally Explained and embed the link in article text.
As long as your link remains in place, we'll keep our link to you right here. Please play fair - our crawlers are watching. Your site must be closely related to this one's topic. Any kind of spamming, dubious practises or removing the link will result in your link from us being dropped and, potentially, your whole site being banned. |
