Improvement of the constant current method; Measure of characteristic parameters of chiral smectic liquid crystals

In ferroelectric liquid crystals, phase transitions can be induced by an electric field. The current constant method allows a fast localization of these transitions and thus to draw up the (E,T) phase diagram of the studied product. In this work we make a light modification to this method. This modification allowed quantitative measurements of certain characteristic parameters of ferroelectric liquid crystals. A new rule of phase was introduced allowing the explanation of phenomenon of coexistence observed into these samples. The use of a current square signal highlights a phenomenon of ferroelectric hysteresis with remnant polarizations at null field which point out an effect of memory in these compounds.