dielectische

Dielectische is a Dutch adjective meaning related to dielectrics, the insulating materials that respond to electric fields by polarization. In physics, a dielectric is a non-conductive substance placed between conductors to influence electric fields, store energy, or serve as insulation. The characteristic properties of dielectische materials include permittivity (ε), relative permittivity εr, electric susceptibility χe, and dielectric strength. The permittivity determines how much electric field is reduced inside the material; ε = ε0εr. Polarization of the material—through molecular orientation, dipole alignment, or distortion of electron clouds—leads to a displacement field D that satisfies D = ε0E + P = εE. Dielectric loss describes energy dissipation as the polarization lags behind the field, quantified by the loss tangent tanδ and its frequency dependence.

Common dielectische materials vary from gases (air), liquids (oil), polymers (polyethylene, PET), to ceramics (alumina). Their εr ranges over several orders of magnitude, with high-εr materials used in capacitors, while high dielectric strength and purity are crucial for insulation. Applications include capacitors, cable insulation, substrates for integrated circuits, and high-voltage equipment.

Dielectric breakdown occurs when the field exceeds the material's breakdown strength, causing conductive failure. Temperature, frequency, and impurities influence performance. Measurements include capacitance methods to derive εr, impedance spectroscopy for loss tangent, and standardized breakdown tests.