Document Type
Article
Publication Date
2-1-1988
Abstract
A variety of ferrodisplacive transitions have Landau expansions which involve terms proportional to p2(p), i.e., three powers of the order parameter (p) and one gradient (). Such expansions have also been suggested for polymeric liquid crystals. We have studied a rotationally invariant, centrosymmetric ferroelectric in which the order parameter is a vector. The pp term leads to modulated phases when it is large enough. The modulated phase close to the uniform-modulated transition and the location of the transition are discussed as a function of dimensionless parameters in a simple model for the free energy. Modifications expected from dangerous irrelevant variables are discussed. The free energy is studied within the d=4- renormalization group. A number of fixed points (always including a stable fixed point) are found as a function of the number of components of the order parameter and the dimensionality of space. The fixed points and the renormalization-group flows are discussed. Finally, the nature of the transition when both mean-field theory and the renormalization group are taken into account is discussed.
Publication Title
Physical Review B
Rights
© 1988 The American Physical Society.
Recommended Citation
Transitions and Modulated Phases in Centrosymmetric Ferroelectrics: Mean-Field and Renormalization-Group Predictions. Hinshaw Jr. G.A., Petschek R.G., Physical Review B 37:4, 2133-2155 (1988).