Plasma Frequency of Bulk Silver in Terahertz Range

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Discussion Overview

The discussion revolves around the plasma frequency of bulk silver, specifically seeking measured values in the Terahertz range. Participants explore various sources and calculations related to the topic, including theoretical equations and empirical data.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Homework-related

Main Points Raised

  • One participant requests measured values for the plasma frequency of bulk silver in the Terahertz range, expressing difficulty in finding consistent data.
  • Another participant suggests a Google search, which the original poster indicates has yielded conflicting values ranging from 1300 THz to 24 THz.
  • A later reply references a common textbook value related to the plasma frequency, noting that it depends on wavelength but clarifying that a specific wavelength is needed for the original inquiry.
  • One participant provides a calculated plasma frequency of 2.17 * 10^15 Hz, derived from a specific equation, and discusses the parameters involved in the calculation.
  • Another participant mentions a range of plasma frequencies in electronvolts (eV) and questions the validity of their calculations, referencing a reflection minimum found in literature.
  • Discussion includes a critique of the jellium model used in calculations, suggesting it is an approximation that may not yield precise results for real systems.
  • A participant inquires about the plasma frequency of doped silver, asking specific questions regarding doping concentration and conversions between frequency and energy units.
  • One participant expresses frustration with repeated suggestions to perform a Google search, criticizing the lack of substantive responses in the thread.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the plasma frequency values, with multiple conflicting figures and models presented. There is ongoing debate regarding the applicability of theoretical models to real-world scenarios.

Contextual Notes

Participants express uncertainty regarding the accuracy of various models and calculations, particularly in relation to doping effects and the limitations of theoretical approaches. Some assumptions about the parameters used in calculations remain unaddressed.

Who May Find This Useful

This discussion may be of interest to researchers and students in materials science, condensed matter physics, and those studying optical properties of metals.

luke
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Does anyone know where I can find measured values for the plasma frequency of bulk silver? I would like them to be for light in the Terahertz range. I have looked in all type of book of optical constants and I have searched many different articles. Just a suggestion of where to look would be nice. Thanks
 
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do a google search under silver plasma frequency...
 
Yeah I have searched google. My only problem is that I have seen values that range from 1300 THz to 24 THz. To just have a value that is within an order of magnitude would be good. Thanks for the reply
 
thank you for your help since the suggestion to do a google search lead me to an article which states "For bulk silver a value of 1 / τ = 2.4 × 10^13 s− 1, is the common textbook value used to fit the plasmons resonance near 400 nm." Well this reminded me that the plasma frequency depends on the wavelength but for what I am doing I do not need the plasma frequency for any wavelength I just need it for a single wavelength. So I think this problem is solved since I was searching for something I didn't need.

Thanks again
 
plasma frequency of silver

The plasma frequency of silver is 2.17 *10^15 Hz or 138 nm. This is calculated from the equation plasma frequency = sqrt(4*pi*N*e^2/m_0), where N is the number of electrons per cm^3, e = 4.8E-10 esu, m_0 is the electron mass m_o=9.11E-28 grams. The plasma frequency will be in Hertz or 1/sec.

Tau is the momentum scattering time. A good explanation is in Mark Fox's book "Optical Properties of Solids".
 
Dr Transport said:
do a google search under silver plasma frequency...

Brilliant! A simple yet effective way to find the answer to everything!
 
Plasma frequency for silver : 3.75(eV)-3.80(eV)

reference:
1. Phys. Rev. 132, 1599 - 1602 (1963)
2. Phys. Rev. Lett. 5, 470 - 472 (1960)

I try to use the formula suggested by Marcie, using n=5.86*10^22 (cm^-3) (from the book by Ashcroft) and I get 8.99(eV).

Well, I hope someone can tell me why the formula doesn't work. I found an article saying that there is a reflection minimum at 9.2(eV). See :Phys. Rev. 121, 1100 - 1103 (1961). I am not sure if the 9.2 eV has anything to do with the calculated 8.99eV.
 
The equation in Ashcroft & Mermin is for the case of a free electron gas in the presence of a uniform positive background (i.e. the jellium model). It is only an approximation of the real system, so it will never give you the "correct" answer. It does a pretty good job though, especially for simple metals at STP.
 
for quantasham,
For pure SIlver it will be the value you calculated. But for doped Silver which is a semiconductor its value is nearly 9 ev.

I need plasma frequency for all the doped semiconductor for my research. My question is
1) Is there a range for maximum and minimum doping of a semiconductor?
2) Plasma fy= sqrt(4piNe^2/m0); Is N the doping concentration in case of doped semiconductor?
3) how to convert frequency in Hertz to ev?

Kindly reply
 
  • #10
Dr Transport said:
do a google search under silver plasma frequency...
Thank you for wasting my time. My unrelated google search for 'Plasma frequency of silver' has this discussion as the first hit. Your useless reply has contributed in destroying the internet. Good job.
 

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