Calculation of electric field–temperature (E,T) phase diagram of a ferroelectric liquid crystal near the SmA–SmC_α~* transition

In this work we perform a theoretical calculation in order to reconstitute the(E–T) phase diagram of a chiral smectic liquid crystal in the vicinity of the SmA–SmC_α~* transition. This reconstruction is carried out on the basis of a thermodynamic calculation of the slope of the curve joining the SmC_α~* domain and the unwound SmC~*. An empiric correction of the mean field term of Landau De-Gennes development is necessary to accomplish this reconstruction. Thereafter, an experimental validation is performed to verify our calculations.