Critical linear thermal expansion in the smectic-A phase near the nematic-smectic phase transition.

Nematic Order near a Tricritical Nematic - Smectic a Phase Transition

The nematic to smectic A (NA) phase transition in liquid crystals has been a subject of extensive study in recent years. The original theories due to McMillan [ I] and de Gennes [ 21 suggested that this transition could be first or second order. De Gennes, using a Landau expansion of the smectic free energy, emphasized the coupling between the smectic or density order parameter, v and the nemat...

Defect model of the smectic A-nematic phase transition

2014 It is shown that phase transitions in three dimensions breaking up an ordered state by polar defect lines can be modelled on the xy model, at least if the interaction of the lines is only steric. The analogy is established for a lattice model by means of a xy high-temperature expansion for spin 1/2. The defect model is applied to the smectic A-nematic transition which is interpreted as a b...

Gauge-dependent critical properties of the nematic to smectic-A phase transition in the 1/N-expansion

Light scattering from the free surface near a second order nematic to smectic a phase transition

2014 We have studied the spectrum of light scattered by surfaces waves thermally excited on the free surface of a nematic liquid crystal in a magnetic field near a second order nematic to smectic A phase transition. We have measured the surface tension and three viscosity coefficients. One of the viscosities diverges and its critical behaviour has been followed to within 3 mK of the transition....

Surface freezing and a two-step pathway of the isotropic-smectic phase transition in colloidal rods.

We study the kinetics of the isotropic-smectic phase transition in a colloidal rod/polymer mixture by visualizing individual smectic layers. First, we show that the bulk isotropic-smectic phase transition is preceded by a surface freezing transition in which a quasi-two-dimensional smectic phase wets the isotropic-nematic interface. Next, we identify a two-step kinetic pathway for the formation...