The spontaneous polarization of some dielectric crystal under the action of external electric field is called ferroelectricity. This is caused by the electric dipole moment produced by the crystal structure, which makes the gravity centers of positive and negative charges not coincide. The relationship between spontaneous polarization and electric field presents a hysteresis curve similar to that of magnetic hysteresis with orientation of external electric field, polarization and electric field. Objects with ferroelectricity are called ferroelectric body; It has a hysteresis loop and a curie point. Above the curie point, it obeys the Curie Weiss law and has ferroelectric domain. ferroelectricity materials include single crystal, polycrystal, inorganic and organic materials. Barium titanate, lead titanate and potassium niobate are typical ferroelectric body. ferroelectric body have many applications in piezoelectric, dielectric, pyroelectric and electrostrictive fields.
Fundamental of Material Science -> Physical and chemical basis of materials