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Modeling the dielectric constant of a material

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Old   July 17, 2020, 14:00
Default Modeling the dielectric constant of a material
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Daniil
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I simulate the electromagnetic properties of a new material that contains very small metal particles (about 100 nm). This material is called PPAN.
I have the following material characteristics: dielectric constant, dielectric loss, conductivity and magnetic permeability (about 1).

Why do I need a model?
I have the characteristics of the PPAN material.
And also I have experimental data on the throughput of PPAN with Fe-Co metal alloy.

I am studying how well the structure absorbs electromagnetic radiation with the addition of different metals. I need to find the best concentration for absorbing electromagnetic radiation and the best metal for this. If this is not possible, then create the most accurate model.


I created a model in the Komsomol.

Unfortunately, it is not possible to simulate that many small particles (a few milliands) and I replaced them with 100 metal circles. The total area of ​​the circles in the model is proportional to the volume of the metal in reality. (20% is occupied by circles in the cut and 20% is occupied by metal in the material in the experiment).

The model is my material - PPAN 2 mm wide. He is surrounded by air. Inside the PPAN there is a cut, in which there are 100 small metal circles. They replace millions of pieces of metal. Electromagnetic waves from 3 GHz to 40 GHz are successively incident on the structure from above. The structure is surrounded on all sides by endless periodic walls.


In the model, I only track parameters like s11 and s21. s11 is the amount of energy reflected from the model in dB, s21 is the amount of transmitted energy in dB. Unfortunately, I cannot find what other parameters of the electromagnetic wave can be tracked.

What am I asking?
I ask you to check this model on formal grounds. Perhaps there is some technical error, not a scientific one.

It is very interesting how to display how much in% of 100% energy was absorbed, how much was reflected, how much passed.


Any feedback is important to me! Thanks for reading!
Link to cloud with model:


https://cloud.mail.ru/public/4iHP/5KkZYESPN
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Old   July 17, 2020, 14:04
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S parameters plot
Attached Images
File Type: jpg Sparam 1111.jpg (90.8 KB, 5 views)
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Old   July 23, 2020, 11:46
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1) https://cloud.mail.ru/public/4iHP/5KkZYESPN - I supplemented the folder with a picture of PPAN interspersed with FeCo
2) It is a dielectric, the electrical conductivity and dielectric properties of which can be regulated by adding various additives such as metals or nanotubes, etc.
3) http://rdo.psu.ac.th/sjst/journal/24...ylonitrile.pdf - A bit wrong, but it describes how it turns out.

It is obtained by pyrolysis from polyacrylonitrile under special conditions.
First, it is dissolved in dimethylformamide. Then pyrolyzed at 800 degrees.
Its structure is exactly like graphene. It's just as flat. However, in some nodes of the rings, nitrogen is randomly located. If you continue to keep the temperature high, you get graphene.
I have never seen PPAN live. But they say it's just black powder. It is very poisonous because it easily turns into fine dust.
This powder with metal particles is diluted with paint and the walls are painted in special rooms. This paint absorbs electromagnetic radiation emanating from computers. (This is as one of the applications.)
Yes, it seems that everything has been used for a long time, but there is no terrorist base under these developments. So I make up for these losses).

http://rdo.psu.ac.th/sjst/journal/24-Suppl-1/10polyacrylonitrile.pdf -
A bit wrong, but it describes how it turns out.

Foreign literature on this issue dates back to the 70s and ends in 2000. If you cannot open the article, use sci-hub.st

Data for the model in the Comsol
Electrical conductivity 3.7[S/cm]
Relative permittivity (imaginary part) 1.5
Relative permittivity (real part) 16.2
Relative permeability 1

What else would you like to know?
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Old   September 5, 2020, 14:55
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The dielectric response function is one of the fundamental properties of materials, which can give an insight into optical and electric properties.
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Old   September 14, 2020, 14:18
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Quote:
Originally Posted by Pavan355 View Post
The dielectric response function is one of the fundamental properties of materials, which can give an insight into optical and electric properties.
Hello!
Thanks for your reply. This is the only answer in such a long period of time.

Can you check the model for errors? Of course it will no longer be free for me.
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