2018年12月16日 · $\begingroup$ For an ideal dielectric, yes you can apply any voltage you want and it will remain an insulator. Of course no real material is an ideal dielectric. Real dielectrics “break down” (become conductors) at high enough voltages. A natural example is air breaking down which causes lightning. $\endgroup$ –

2016年2月18日 · Dielectric constant is proportional to the ratio of polarization density (P) and electric field (E) which means dielectric constant is inversely proportional to electric field. The Electric field (E) inside a conductor is always zero under the static situation so the dielectric constant for conductor is infinite.

Breakdowns are electron cascades. There are different kinds: 1) Intrinsic breakdown of the material occurs when the electric field is sufficiently strong to ionize an atom of the dielectric (or accelerate a stray electron sufficiently to do the same), with the resultant new free electrons then being accelerated by the field to repeat the process with another atom.

2016年1月9日 · In other words, permittivity is a measure of how an electric field affects, and is affected by, a dielectric medium. Yes, metals have infinite permittivity as they completely negate the electric field inside their bulk. I.e. infinite resistance to …

2017年4月29日 · Think of a dielectric inside a parallel plate capacitor with one positive and one negative plate. The negative charges inside the dielectric will be attracted towards the positive plate of the capacitor while the positive charges will be attracted towards the negatively charged plate of the capacitor, however these charges can travel only so far inside the dielectric, but if …

2025年1月28日 · Sputtered Pt electrodes were previously used, and now using Cu electrochemically deposited electrodes; these are better showing no resistance across the surface and approx. 500k ohms at RT through the CCTO dielectric of …

2021年1月19日 · As the dielectric constant of the plates are different, I would expect a surface density at the interface of the two dielectric materials. I want to calculate this surface charge density. I have the following figure in my mind but with two different slabs of dielectrics (area and length are the same).

2019年2月12日 · A dielectric with high permittivity $\varepsilon$ permits (requires) more polarization for a given field magnitude than a low permittivity one. More polarization means more charge stored, so the high $\varepsilon$ material must hold more charge for a given field to be measured across it when used as a dielectric in a capacitor.

2018年5月25日 · An amorphous, granular, or otherwise macroporous or matrix material has no reciprocal lattice -- boundary or other effects will dominate the optical properties. Pure dielectric crystals will generally be transparent to photon energies lower than their bandgap. $\endgroup$ –

2015年1月3日 · I have trouble understanding the points / advantages of a dielectric from what I have read in a text book. The points written there are: The mechanical advantage of seperating the plates in practice. Any insulator will experience dielectric breakdown at some point, so picking a dielectric other than air can make it tolerate higher voltage.