Critical behavior at the nematic to lamellar phase transitions: A synchrotron x-ray scattering study

摘要

The nematic (N) to lamellar (L-alpha) phase transition in binary mixtures of cesium-perfluoro-octanoate (CsPFO) and water has been studied by high-resolution synchrotron x-ray scattering at 46.6 weight % CsPFO. The longitudinal correlation length xi(parallel to) and the susceptibility sigma associated with the lamellar phase fluctuations in the N phase, measured over three decades of reduced temperature, diverge with critical exponents nu(parallel to) = 0.86 +/- 0.04 and gamma = 1.37 +/- 0.11, respectively. These results show that the N to L-alpha phase transition is quantitatively similar to the N to smectic-A phase transition of thermotropic liquid crystals with a wider nematic range. [References: 21]