Other Types of Modulated Structures

The formation of transient domain patterns aligned perpendicular to the initial director during the relaxation process of the Frederiks transition has been known since the earliest observations by Carr [20] and Guyon et al. [21]. After these observations some other transient domain structures were found in thermotropic and lyotropic liquid crystal with perpendicular [22], parallel [23], oblique [24], and two-dimensional [25] striped patterns relative to the initial orientation of the director in both the electric and magnetic fields. 

The physical origin of these phenomena could be explained by faster response times of the modulated structures, as compared with uniform ones. When the equilibrium director distribution is approached, i.e., a relaxation process is over, the transient structures disappear. The emergence and subsequent evolution of the spatial periodicity of the transient structures were considered theoretically in [26] for different domain orientations with respect to the initial homogeneous and twisted director structure. 

Modulated structures in the Prederiks transition could also arise in the case where a splay elastic constant Kn is large compared to the twist 

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