Effects of surface modification on the critical behaviour in multiple-surface-layer ferroelectric thin films

Abstract

Using the usual mean-field theory approximation, the critical behaviour (i.e. the Curie temperature Tc and the critical surface transverse field Ω sc ) in a multiple-surface-layer ferroelectric thin film is studied on the basis of the spin- transverse Ising model. The dependence of the Curie temperature Tc on the surface transverse field Ω s and the surface layer number Ns are discussed in detail. Meanwhile the dependence of the critical surface transverse field Ω sc on the surface layer number Ns is also examined. The numerical results indicate that the critical behaviour of ferroelectric thin films is obviously affected by modifications of the surface transverse field Ω s and surface layer number Ns.