Ferroelectric superlattice with first-order phase transition

Abstract

The Mean field expressions derived from the transverse Ising model are presented to describe the first-order ferroelectric phase transitions. The theory is used to discuss the static properties of ferroelectric superlatticcs formed by inserting periodically a monolayer of material B into material A; the bulk properties of material B are assumed paraelectric. Both the Curie temperature and the critical value of the spin average are dependent sensitively on the period of the superlattice when the period is small. For the case of large period, the Curie temperature is reduced slight compared with the bulk value of material A; while the spin average is reduced remarkably.