dielektrischer

Dielektrischer is a German term associated with dielectrics in physics and engineering. It denotes materials or properties related to dielectric behavior, where an insulating substance responds to an applied electric field primarily through polarization rather than charge conduction.

Dielectrics are non-conductive materials that can be polarized by an electric field, reducing the internal field and allowing energy to be stored. The key material property is permittivity, usually expressed as the vacuum permittivity ε0 multiplied by the relative permittivity εr. Dielectrics may be classified as nonpolar or polar, reflecting different polarization mechanisms: electronic and ionic polarization in both, and additional orientational polarization in polar dielectrics at lower frequencies.

The relative permittivity and the dielectric strength determine a material's usefulness in applications such as capacitors, insulators in cables, and dielectric resonators. Dielectric losses, frequency dependence, moisture, temperature, and aging affect performance. In practice, engineers select dielectrics to balance high energy storage, low loss, and adequate breakdown voltage for a given application.

In theory, dielectrics are treated within Maxwell's equations with the displacement field D = ε E. The energy stored in a dielectric under an electric field is (1/2) ε E^2, and the material's behavior is summarized by its dielectric constant or relative permittivity. Examples include air, glass, ceramic, and many plastics.