Monte Carlo study with reweighting of uniaxial nematic liquid crystals composed of biaxial molecules.

We present a high accuracy Monte Carlo simulation study of the uniaxial nematic (N_{U}) to isotropic (I) phase transition of a lattice dispersion model of uniaxial nematics composed of biaxial molecules. The N_{U}-I coexistence curve terminating at the Landau critical point has been determined using the multiple histogram reweighting technique. A close investigation reveals a sharp departure in the nature of the N_{U}-I coexistence curve in the temperature-biaxiality parameter phase diagram in comparison to the earlier theoretical (either mean-field or computer simulation) predictions.

Pressure-induced phase transitions in liquid crystals: A molecular field approach.

A rigorous microscopic treatment of a nematic fluid system based on a pairwise interaction potential is immensely complex. For studying such systems molecular field theories are often the standard method of choice. In this paper we have chosen a simple effective potential U=u_{4}/v^{4}-u_{2}/v^{2}-Au_{2}/v^{2}〈P_{2}〉P_{2}(cosϑ) to study an isothermal-isobaric ensemble describing a liquid crystalline system.

Monte Carlo investigation of critical properties of the Landau point of a biaxial liquid-crystal system.

Extensive Monte Carlo simulations are performed to investigate the critical properties of a special singular point usually known as the Landau point. The singular behavior is studied in the case when the order parameter is a tensor of rank 2. Such an order parameter is associated with a nematic-liquid-crystal phase.

Effect of an external magnetic field on the nematic-isotropic phase transition in mesogenic systems of uniaxial and biaxial molecules: a Monte Carlo study.

We determine the nematic-isotropic coexistence curve terminating at the critical point in a temperature-external field phase diagram for nematic liquid crystals with positive diamagnetic anisotropy, where the molecules are either perfectly uniaxial or biaxial using computer simulation of a lattice model. The coexistence curve is much steeper than that predicted by the standard Landau-de Gennes and Maier-Saupe mean-field theories. For the uniaxial system the critical magnetic field is estimated to be one order of magnitude lower than the mean-field estimate but of the same order of magnitude as the experimental measurement.