I am trying to find out the exact value of Fermi energy of Molybdenum. Unfortunately, I am unable to find any reliable value mentioned in any literature.
Dear Colleague Subheangsu,
You get the position of Fermi level of any metal measured from the vacuum level free electron level by defining the work function since by definition the work function is the energy required to transfer an electron from the Fermi level to the free electron level in vacuum.
Accordingly the value given in the literature for the workfunction of molybdenum= 4.37 electronvolt.
Best wishes
Dear Prof. Zekry,
Thank you for your reply. However, I am looking for the value of Fermi energy instead of work function. I need the absolute value of the maximum occupied energy level in Molybdenum at 0K. As per example, Ag has a Fermi energy of 5.52 eV (Ashcroft and Mermin, pg. 38), while it has a work function of 4.26-4.73 ( Tipler & Llewellyn, Ch 3).
I agree with dr. Zekry - the work function gives you Fermi level position. But you should take into account that different work functions corresponds to different crystalline structures: 111 and 100 faces of Mo crystal have different WF, as well as amorphous Mo.
Dear Colleagues,
welcome,
It is the matter of the reference level to which you measure the Fermi level. There is no absolute Fermi- level. Either you measure it with reference to the vacuum level or you measure it with reference to the bottom of the conduction band in case of metals.
Best wishes
Dear Prof. Zekry and Prof.. Yuriy Kudriavtsev,
Thank you for your replies. I want to know how to arrive at an average Fermi energy of Molybdenum as given for other metals in Ashcroft and Mermin, pg. 38. Is there any physical quantity I can measure or simulate?
Or, is there any way I can simulate the Fermi wave vector, from which I can calculate the value of Fermi energy? Is DFT based calculations accurate enough for these kinds of prediction?
Dear Prof. Zekry and Prof. Yuriy Kudriavtsev,
If I know the Fermi energy of one metal and it's difference in work function with Molybdenum, can I calculate Fermi energy of Molybdenum from that?
Dear Collegue,
You can calculate the Fermi energy at zero kelvin with reference to the bottom of the conduction band edge if you know the electron density n of the metal. Please refer to the link: http://hyperphysics.phy-astr.gsu.edu/hbase/Solids/Fermi2.html
I think this is the Fermi energy which you mean.
Best wishes
Dear Prof. Zekry,
Yes. This is the Fermi energy I want. But I have no prior knowledge of the electron density of the material. I only know that the resistivity of the material is ~10^-7 Ohm.m.
Dear respected Colleage,
You estimate the electron density from the atomic density of the material and its valency.
To calculate the density of atoms per cm^3 N you can use the formula:
N = N A x roh/ Atomic weight ,
where NA Avogadro number , roh is the density in g/cm^3, Atomic weight in g/ atomic weight.
The Avogadro number= (6.022 x10^23 atoms / molecular weight,
roh= 10.2 g/cm^3,
Atomic mass = 95.94,
N= 6.4 x 10^22 /cm^3 ,
The valency of Molybdenum is one according to its electronic configuration
[Kr] 4d55s1 ,
So n the electron concentration= atomic concentration N= 6.4 x 10^22 /cm^3
Please use this electron concentration to calculate the Fermi level according to the formula given in the previous post.
Best wishes
Hi Subhrangsu Sarkar
I came to know this reference for Fermi energy and density of states for Mo (you just need to convert the unit from Ry to eV). My answer is very late but could be helpful for others.
Thanks
Ayesha
https://books.google.ie/books?id=8tlEAAAAIAAJ&pg=PA53&dq=fermi+energy+of+molybdenum&hl=en&sa=X&ved=2ahUKEwiq_f3-yLTqAhUbTxUIHWe3CQ4Q6AEwAHoECAUQAg#v=onepage&q=fermi%20energy%20of%20molybdenum&f=false
Ayesha Sharif : Thank you! It is never too late to know something. :)
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