Alternate Definitions for ferroelectric

Definition: A ceramic material with a switchable spontaneous polarization via positively and negatively biased electric fields, due to weird behaviors of charge density in noncentrosymmetric dielectric crystals

Example: Hafnia, PZT, AlScN

Definition: A material that exhibits spontaneous electric polarization that can be reversed by an external electric field.

Example: Lead Zirconate Titanate (PZT) is a widely used ferroelectric ceramic in sensors and actuators.