File:Capacitor_schematic_with_dielectric.svg · Wikimedia Commons · See Wikimedia Commons

EntityQ184996· pop 64· linked from 730 articles

dielectric

Also known as dielectric medium

thumb|A polarised dielectric material (orange), between two metal plates

AI overview

A dielectric is a material that doesn't conduct electricity but can be polarized—meaning its electric charges shift slightly when placed in an electric field. Dielectrics are useful in devices like capacitors, where they're placed between metal plates to store electrical energy more effectively.

AI-generated from the Wikipedia summary — may contain errors.

Wikidata facts

Show 1 more fact

Commons category: Dielectric material

Sources (3)

via Wikidata · CC0

~25 min read

Article

23 sections

Contents

Terminology
Electric susceptibility
Dispersion and causality
Dielectric polarisation
Basic atomic model
Dipolar polarisation
Ionic polarisation
In biological cells
Dielectric dispersion
Dielectric relaxation
Debye relaxation
Variants of the Debye equation
Paraelectricity
Tunability
Applications
Capacitors
Dielectric resonator
BST thin films
Some practical dielectrics
See also
References
Further reading
External links

thumb|A polarised dielectric material (orange), between two metal plates

In electromagnetism, a dielectric (or dielectric medium) is an electrical insulator that can be polarised by an applied electric field. When a dielectric material is placed in an electric field, electric charges do not flow through the material as they do in an electrical conductor, because they have no loosely bound, or free, electrons that may drift through the material, but instead they shift, only slightly, from their average equilibrium positions, causing dielectric polarisation. Because of dielectric polarisation, positive charges are displaced in the direction of the field and negative charges shift in the direction opposite to the field. This creates an internal electric field that reduces the overall field within the dielectric itself. If a dielectric is composed of weakly bonded molecules, those molecules not only become polarised, but also reorient so that their symmetry axes align to the field.