Definition of Ferroelectrics and Antiferroelectrics

A ferroelectric crystal is defined as a crystal which belongs to the pyroelectric family (i. e. shows a spontaneous electric polarization) and whose direction of spontaneous polarization can be reversed by an electric 

5 -1 Ferroelectric hysteresis loop. Ps, spontaneous polarization Pj, remanent polarization Ec, coercive field 

The spontaneous polarization in ferroelectrics and the sublattice polarizations in antiferroelectrics are analogous to their magnetic counterparts. As described above, however, these polarizations are a necessary 

5-2 Antiferroelectric hysteresis loop. crit, critical field 

The definition of ferroelectric liquid crystals needs some comments see remark / in Sect. 4.5.3.I. 

---