Symmetries and alignment of biaxial nematic liquid crystals

Abstract

The possible symmetries of the biaxial nematic phase are examined against the implications of the presently available experimental results. Contrary to the widespread notion that biaxial nematics have orthorhombic symmetry, our study shows that a monoclinic ($C_{2h}$) symmetry is more likely to be the case for the recently observed phase biaxiality in thermotropic bent-core and calamitc tetrapode nematic systems. The methodology for differentiating between the possible symmetries of the biaxial nematic phase by NMR and by IR spectroscopy measurements is presented in detail. The manifestations of the different symmetries on the alignment of the biaxial phase are identified and their implications on the measurement and quantification of biaxiality as well as on the potential use of biaxial nematic liquid crystals in electro-optic applications are discussed.

24 pages, 4 figures

References in corpus (2)

• Thermotropic Biaxial Nematics: Spontaneous or Field-Stabilized?
• Biaxial nematics: symmetries, order domains and field-induced phase transitions

Cited by in corpus (8)

• A Molecular Theory of the Nematic-Nematic Phase Transitions in Mesogenic Dimers
• Extending the Maier-Saupe theory to cybotactic nematics
• Atomistic simulations of nematic phases formed by cyano-biphenyl dimers
• Twisted quasiperiodic textures of biaxial nematics
• Complete integrability and equilibrium thermodynamics of biaxial nematic systems with discrete orientational degrees of freedom
• On the isotropic-biaxial phase transition in nematic liquid crystals
• On one dimensional inverse problems arising from polarimetric measurements of nematic liquid crystals
• Probing a non-biaxial behavior of infinitely thin hard platelets