Abstract

The biaxial smectic-A* (Sm-AB*) phase, appearing in the phase sequence Sm-A*–Sm-AB*–Sm-C*, is analyzed using Landau theory. It is found to possess a helical superstructure with a pitch that is significantly shorter than the pitch of the Sm-C* helical superstructure. The Sm-AB*–Sm-C* transition can be either first or second order, and correspondingly there will be either a jump or continuous variation in the pitch. The behaviors of the birefringence and electroclinic effect are analyzed and found to be similar to those of a Sm-Cα* phase. As such, it is possible that the Sm-AB* phase could be misidentified as a Sm-Cα* phase. Ways to distinguish the two phases are discussed.

Disciplines

Physics

 

URL: http://digitalcommons.calpoly.edu/phy_fac/345