Do Material Properties Follow a Linear Response Pattern?

AI Thread Summary
The discussion centers on the relationship between material properties and the applied electric field, particularly in dielectric materials. It highlights that while the permittivity of these materials changes with the electric field, a linear response is observed when an alternating electric field is applied, resulting in a clean sine wave output. This raises questions about the nature of this linear response, especially when considering the range of electric field values leading up to the set amplitude. Key points include the potential frequency dependence of the response, with linear behavior at lower frequencies (e.g., 10 kHz) potentially becoming nonlinear at higher frequencies (e.g., 100 MHz). The conversation also touches on the importance of capacitance in experimental setups and the effects of different waveforms, such as square or triangle waves, on the response. Revisiting established models like the Drude model is suggested for further understanding.
EE4life
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Hi all,

I have a general question about material properties.

We know that the material property value depends on the input level. For example, the permittivity in a dielectric material changes depending on the applied electric field.

That being said, when we apply an alternating electric field, we receive a linear response while at the same time the electric field is going from 0 to the set amplitude. We go through a range of electric fields values before arriving at the final amplitude, yet we still receive a nice sine wave output which is indicative of a linear response.

This leads to the obvious conclusion that, for the "linear range" , we get a linear response depending on the amplitude of the input. At the moment, I cannot understand this. I would imagine the response would not be a clean sine wave (for a AC input) because the changing properties due to changing electric field.

Am I missing something here?
 
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You might check handbooks, Giacoletto comes to mind, for the properties which interest you.
 
Is there a frequency dependence?
i.e. linear response at 10 kHz but nonlinear response at 100 MHz?
Do you have to worry about capacitance in your experimental set up?
Is there an amplitude dependence? How high of a set point before you get a nonlinear response?
If you apply a square wave or a triangle wave in your AC signal, do you get the same response?
revisit The Drude model.
 
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