Shcherbakov K. Spatially-Modulated Phases induced by the flexoelectric effect in ferroics

The influence of the flexoelectric effect on generalized susceptibility and soft phonon modes in the ordered phase of ferroics is established. Conditions of appearance and stability of spatially-modulated phases in ferroelectrics and in liquid crystals were found. It is shown that the fundamental upper restrictions on the magnitude of static flexoelectic coefficients that were established without taking into account the square of the gradient of elastic strain should be replaced by temperature dependent conditions that are imposed on the flexoconstant. The influence of flexoelectric coupling on the dynamics of the local electromechanical response of semiconductors with electron-ionic conductivity is found. The influence of the flexoelectric coupling on the director's orientation and polarization in nematic liquid crystals have been established.