Spontaneously bended nematic and antiferroelectric smectic structures of banana-shaped hard particles in two dimensions
Instituto de Química, Universidad Nacional Autónoma de México - Apdo. Postal 70213, 04510 Coyoacán, México D.F., México
2 Institute of Physics and Mechatronics, University of Pannonia - PO Box 158, Veszprém, H-8201 Hungary, EU
Accepted: 6 December 2011
Spontaneously deformed nematic and antiferroelectric smectic structures have been detected in a two-dimensional system of hard banana-shaped needles by means of Monte Carlo simulation and Onsager theory. The spatially non-uniform and deformed nematic consists of orientationally ordered polar domains, where the nematic director displays mainly bended patterns. The net polarization of the bended nematic is zero. Onsager theory shows that the bent-core structure of the particles favours the bend deformation due to a free energy reducing bend torque, while the splay deformation results in a free energy cost. With increasing pressure the polar nematic domains becomes thinner and transforms into linear arrays with alternating polarity (antiferroelectric smectic phase). The theoretical results are in good agreement with the simulations.
PACS: 64.70.mf – Theory and modeling of specific liquid crystal transitions, including computer simulation / 61.30.Cz – Molecular and microscopic models and theories of liquid crystal structure / 05.20.Jj – Statistical mechanics of classical fluids
© EPLA, 2012