Ferroelektrische

Ferroelektrische materials exhibit spontaneous electric polarization that can be reversed by applying an external electric field. This characteristic makes them distinct from other dielectric materials. The spontaneous polarization arises from the alignment of electric dipoles within the crystal structure, which can occur even in the absence of an applied electric field. When an electric field is applied, these dipoles can be reoriented, leading to a change in the net polarization. If the direction of the applied field is reversed, the polarization can also be reversed. This phenomenon is known as hysteresis.

The temperature at which a ferroelectric material loses its spontaneous polarization and transitions to a paraelectric state is called the Curie temperature. Above the Curie temperature, the thermal vibrations of the atoms overcome the forces that align the dipoles, and the material behaves as a normal dielectric. Ferroelectric materials have found applications in various technologies due to their unique properties. They are used in non-volatile memory devices (FeRAM), actuators, sensors, and tunable microwave devices. The ability to store information in the polarization state and to convert electrical energy to mechanical energy, or vice versa, makes them valuable components in modern electronics. Research continues to explore new ferroelectric materials with improved properties and novel applications.