Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

What determins the electrical resistivity of different metals?

  1. Mar 3, 2008 #1
    The resistivity arises because the electrons collide with atoms so they flow slower. The resistivity of different metals differ a lot. What determines the electrical resistivity of different metals? It is related to their structure? How?
  2. jcsd
  3. Mar 3, 2008 #2
    For some reason I thought it depended upon the amount of electrons in the conduction band. Certainly losses through collisions must play a part. Thus perhaps the amount of electrons/holes that are free to conduct as well as the mean free path.
  4. Mar 3, 2008 #3
    It depends greatly on the material, (metals, semiconductors, insulators).
    In metals, the argument to increasing electrical resistivity with temperature is the one you pointed (roughly speaking): electron keep bumping into each other , making electron progression more difficult.
    In general, the electrical resistivity in metals doesn't vary that much (maybe ~1 order of magnitude).
    If I remember correctly, different resistivities in metals are primary due to different metals having a different number of outer electrons, and different densities. (if each atom occupies less space, the number of electrons it provided will have more "bumps" on average).

    When we talk about semiconductors, the electrical properties are a lot different. There are not many free electron around, and when you increase temperature, you actually increase the number of electrons available to create the current.
    Depending on how easy it is to get out these free electrons from the semiconductors, the electrical resistivity varies, so semiconductors have very different electrical resistivities.
    Last edited: Mar 3, 2008
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook