Paraelektrikussá

Paraelektrikussá is a term used in physics, specifically in the study of dielectrics. It describes the state of a material where the constituent molecules or atoms possess permanent electric dipole moments, but these dipoles are randomly oriented in the absence of an external electric field. When an external electric field is applied, these dipoles tend to align themselves with the field, leading to a net polarization of the material. This alignment is not permanent; once the external field is removed, the dipoles return to their random orientation due to thermal agitation. Materials that exhibit this behavior are called paraelectric. Unlike ferroelectric materials, paraelectrics do not exhibit spontaneous polarization or hysteresis. Their dielectric constant is typically temperature-dependent, decreasing as temperature increases due to increased thermal motion counteracting dipole alignment. Examples of paraelectric materials include many alkali halides at high temperatures and certain perovskite structures above their ferroelectric transition temperature. The phenomenon is crucial for understanding the dielectric properties of various substances and has applications in areas like capacitors and sensors.