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

Arrhenius plot and activation energy

  1. May 9, 2013 #1
    I m trying to determine activation energy of donor levels .
    So i have measured absorption at different temperatures of my sample (mono-crystal)

    And I have plotted ln(optical density) vs 1/T(K).
    And I want to calculate activation energy useing

    In plot above (picture) Eactivation should be 0.043eV

    The problem is that I cant get the right answer.
    Could someone help me,and derive the mentioned formula above for Ea determination? Maybe Im doing it wrong.
  2. jcsd
  3. May 9, 2013 #2
    Hi prehisto,

    First the scatter in your data should make a large error bar. What is the 95% confidence range of this fitted activation energy?

    Second, I would check things like natural log v.s. decimal log and the units of Boltzmann constant, jsut the basic stuff.
  4. May 9, 2013 #3
    I agree, it makes a large error bar. But in this case it does not matter . This is an example for which i know the result ( for this particular liner fitting).

    i have checked logarithms and Boltzman const.

    Is this the correct formula?
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook