Fluctunoic states of electrons in ferroelectrics-semiconductors and ferro-semiconducting solid solutions

Abstract

The fluctuonic states of electrons in ferrosemiconducting crystals and their solid solutions are considered using the modified landau-ginburg-Devonshire theory that gives the following results.

1.	The functional is obtained which describes the self-consistent state of polarization fluctuation and wave function of the polarizing electron. The dimensionless varibles are used. The task decision is considered for the finite depath spherical pit-type potenitial through the parametric potential. The numerical calculations of thee main charcteristiecs of phasons (radius, polarazation, full energy, energyof localized electron, density of surface energy et al.) depending on temperature are carried out the stabiliity conditions and the temperature range of phason existence are considered.
2.	Some anomalous photogerroelectric phenomena (photorefractive efffect, photoinduced Rayleigh scattering, luminescence et al.) are considered. The calculation of these effects for BaTio3 is carried out basing on the phason model and the agreement with expriment is obtained. The estimates for the complex fluctuons and phasons are given.
3.	It is shown that the ellipsoid-shaped anisotropic phason become the spherical one by introducing the effective radius taking into account the excentricity of an ellipsoid. The potential within the phason is asymmetic and the electron localization region is shiffted againsst the phason centre to its positive pole. The relation between the radis of the electron localization region and the phason radius is obtained. The pahson model of the anomalous photovoltaic effect is proposed basing on the asymmetric phason potential and the agreement with experiment isobtained for BaTio3.