The shielding theory of ferroelectricity

We have developed the theory of boundary shielding approximation of electri c polarization, from which the values of spontaneous polarization of some t ypical ferroelectric materials can be derived. The shielded charges in ferr oelectricity are in the state of surface bound polaron-dipole whose creatio n and annihilation must span a potential barrier. By introducing statistica l method, four types of typical electric hysteresis loops of some common cr ystals and ceramics have been given, which are well consistent with the exp erimental results.