Calcul de la polarisation spontanée dans les phases ferroélectriques de BaTiO3

Abstract

The spontaneous polarization of BaTiO${}_3$ is calculated in ferroelectric phases from a microscopic model taking into account of the dipole–dipole interactions due to the local field acting on the constituent ions, where the Ti ions shift in the lattice having the spontaneous deformation. Our calculation shows that the spontaneous polarization increases when the temperature decreases. These theoretical results are in good agreement with the experimental data.