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B Fermi Energy simplification

  1. Mar 27, 2017 #1
    Here is a simplification of a problem given in my book. I don't get the simplification part.

    Could you please help at this ? It seems book has done the calculation wrongly.

    simplification_zpsu8kjnvmu.jpg
     
  2. jcsd
  3. Mar 27, 2017 #2

    mfb

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    2016 Award

    Staff: Mentor

    6.4/1.381 = 4.634. There is no obvious typo that would lead to 5.624 and the Boltzmann constant is correct. I don't understand the calculation done in the book.
     
  4. Mar 27, 2017 #3
    here is the problem:

    electron_zpspzmpaowo.jpg
     
  5. Mar 27, 2017 #4
    6.4 1020 is the 0.4 eV expressed in Joules.
     
  6. Mar 27, 2017 #5

    mfb

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    2016 Award

    Staff: Mentor

    The 5.624 would correspond to 0.485 eV, 7.77E-20 J, or a wrong Boltzmann constant of 1.138 instead of 1.381.

    Maybe the last one is the cause of the mistake, it can be explained by swapping the digits.
     
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