Arrhenius plot and activation energy


by prehisto
Tags: activation, arrhenius, energy, plot
prehisto
prehisto is offline
#1
May9-13, 02:02 PM
P: 51
Hi,guys.
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
D=D0exp(-Ea/kT)

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.
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Useful nucleus
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#2
May9-13, 02:49 PM
Useful nucleus's Avatar
P: 240
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.
prehisto
prehisto is offline
#3
May9-13, 04:26 PM
P: 51
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?


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