Free and bound charge at dielectric-conductor interface

[youngpm]

Say I have a capacitor filled with a linear dielectric in a purely electrostatic setup. Then there will exist a uniform electric field inside the capacitor, and the field inside the electrodes is of course zero. The dielectric will polarize, and I should get bound charge at the dielectric-conductor interface. It seems to me that you would also get some induced free charge from the conductor as well at this interface.

What kind of coulomb forces would I get in this situation, if what I described is in fact correct?

To generalize my question, what in general happens at a conductor-dielectric interface? How does the induce charge behave? Is there only surface polarization charge from the dielectric, or does induced free charge come into play from the conductor?

Thanks!

 

[Dale]

Actually, you have it exactly backwards. There is an applied charge on the surface of the conductor that causes the E-field between the plates. The dielectric material polarizes in response to this externally applied E-field. For all practical purposes the dielectric is uncharged, including on its surface. Being polarized is not the same as being charged.

 

[astrokreng]

I would first like to clarify that the scenario described in the content is correct. In a capacitor filled with a linear dielectric in a purely electrostatic setup, there will indeed be a uniform electric field inside the capacitor and a zero field inside the electrodes. The dielectric will polarize, resulting in bound charge at the dielectric-conductor interface.

In this situation, the coulomb forces will depend on the properties of the dielectric and the conductor. The bound charge at the interface will experience a force due to the electric field, while the induced free charge from the conductor will also contribute to the overall force. The magnitude and direction of these forces will depend on the dielectric constant of the material, as well as the surface charge density of the conductor.

In general, at a conductor-dielectric interface, both surface polarization charge from the dielectric and induced free charge from the conductor can come into play. The behavior of the induced charge will depend on the properties of the materials involved and the electric field present. It is important to note that the presence of a dielectric can significantly alter the behavior of the induced charge, as it can affect the overall electric field and the distribution of charge.

In conclusion, the behavior of charge at a conductor-dielectric interface is complex and depends on various factors. Further analysis and experimentation may be necessary to fully understand the behavior of induced charge in such a scenario.