dielektriker

Dielektriker is the term used in physics and electrical engineering to refer to dielectric materials, insulating substances that do not conduct electric current under normal conditions but can be polarized by an electric field. When a dielectric is placed in an electric field, charges inside it shift slightly, creating bound charges that modify the field within the material. This polarization allows dielectrics to influence capacitance, insulation, and energy storage in electrical systems.

The key property of a dielectric is its dielectric constant, or relative permittivity (εr), which expresses how much the material reduces the electric field compared to vacuum. The absolute permittivity is ε = ε0 × εr, where ε0 is the vacuum permittivity. Dielectrics exhibit several polarization mechanisms: electronic, ionic, orientational (dipolar), and space-charge polarization, each with characteristic responses to frequency and temperature. Dielectric strength or breakdown voltage indicates the maximum electric field the material can withstand before failing. Dielectrics also have a dissipation factor (loss tangent, tan δ) that describes energy loss as heat, which varies with frequency and temperature.

Common dielectric materials include air, vacuum, ceramics, polymers (such as polyethylene and polypropylene), mica, paper, and oil-impregnated insulations. Ferroelectric and other nonlinear dielectrics exhibit complex behavior, including hysteresis and dielectric relaxation.

Dielektriker are essential in capacitors, insulators for power equipment, cables, and printed circuit boards. Their selection depends on dielectric constant, breakdown strength, losses, temperature stability, moisture sensitivity, and mechanical properties.