(α,η) phase diagrams in tilted chiral smectics

The polymorphism of tilted chiral smectics liquid crystals is incredibly rich and encompasses many subphases such as SmCA⁎; SmCFi1⁎; SmCFi2⁎; SmC⁎; SmCα⁎. The continuum theory established by Marcerou (2010) [1] is used to derive an expression for the free energy density of those subphases. The minimization of this free energy is obtained through a combination of analytical and numerical methods. It leads to a phase diagram built in the (α,η) plane where α is local angular parameter and η describes the variation of the temperature. From this graphical representation, many experimentally observed phase sequences of ferroelectric liquid crystals can be explained, even them including subphases which were recently observed like the SmC5⁎ and the SmC6⁎ ones. However, it should be emphasized that the details of predicted phase diagram are strongly dependent on the compound studied.