Abstract
On the basis of the Gaussian overlap model and the Monte-Carlo method the study of the thermodynamic properties of smectic C liquid crystals (LC) C5H11O-(OH)C6H3-CH = N-C6H4-C5H11 (A), C10H21O-C6H4-CH = CH-C6H4-OC10H21 (B), ferroelectric smectic C* liquid crystals, C7H15O-C6H4-C6H4-COO-CH2C*H(CH3)C2H5 (C), C8H17O-C6H4-C6H4-C2H4C*H(CH3)C2H5(D), and also the equimolar binary systems of {A+C} and {A+D} has been carried out. A smectic C phase was detected at the fixed densities (η = 0,45, where η is the density coefficient) for different temperature values. It is shown in particular, that such ordering is mainly due to the substantial (transversal) dipole moment of A-D molecules. We have also obtained curves of the dependence on temperature for the free energy, configuration energy, specific heat Cv and orientational-order parameter which are in good agreement with the experimentally observed trends in the changes of the smectic and ferroelectric LC properties.