Abstract
Based on Landau-de-Gennes type free-energy density expansion, we study the influence of pressure and temperature on the spontaneous polarisation, tilt angle and smectic A (Sm A) – chiral smectic C (Sm C*) transition temperature () of ferroelectric mesogen p-(n-decyloxybenzilidene)-p′-amino-(2-methylbutyl) cinnamate (DOBAMBC). The pressure dependence of the ferroic properties is incorporated through the pressure dependent Landau coefficients associated with the order parameters coupling terms of the free-energy density expansion. It is found that the application of pressure reduces the stability of Sm C* phase, while the stability of Sm A phase increases. The order parameter coupling terms play an important role and the ferroelectric properties are in good agreement with the available experimental data of DOBAMBC.
Acknowledgement
The financial support received from UGC, New Delhi, and DST, New Delhi, is thankfully acknowledged.