Thermodynamic model to study the structural and electro-optical properties of chiral antiferroelectric smectic C phase exhibited by mesogenic homologous series 3FnHBM6(s) and W-316 mixture

ABSTRACT

Using a thermodynamic model developed by us to study the structural and electro-optical properties of ${\mathrm{Sm}\mathrm{C}}_{\mathrm{A}}^{\ast }$ phase, we investigate the temperature dependence of helical pitch, tilt angle and spontaneous polarization of a homologous series of fluorinated biphenyl benzoate esters (3FnHBM6, n = 2, 5, 7) and one of the series W-316-3 obtained from the mixture of two chiral liquid crystalline compounds 6F2OBi and 3F6HBM6. The free-energy density of the system exhibiting ${\mathrm{Sm}\mathrm{C}}_{\mathrm{A}}^{\ast }$ phase is written as an expansion series in terms of all the relevant degrees of freedom: ${\mathbf{Q}}_{\mathbf{i}\mathbf{j}}$, ψ, P, q and the resulting coupling terms between these order parameters. The values of Landau coefficients are determined from the experimental data of antiferroelectric mesogens 3FnHBM6 (n = 2, 5, 7) and W-316-3 in the $\mathrm{Sm}{\mathrm{C}}_{\mathrm{A}}^{\ast }$ phase. Using these coefficients, the electro-optical and structural properties have been studied. We have found good agreements between the theoretical and experimental results.

KEYWORDS:

• Free energy density expansion
• antiferroelectric liquid crystal
• spontaneous polarizations
• order parameters
• structural properties
• electro-optical properties

Acknowledgement

I would like to acknowledge JSSMVP Mysore for their kind support and encouragement.

Disclosure statement

No potential conflict of interest was reported by the author(s).