title: Slow mode of the smectic-A-smectic-C(*)(alpha) phase transition.
abstract: Unusual slow fluctuations as revealed recently by dynamic light scattering close to the Sm-A-Sm-C(alpha)(*) phase transition in the antiferroelectric liquid crystal 4-(1-methylheptyloxy-carbonyl)phenyl 4(')-octyloxy biphenyl-4-carboxylate can be explained by the electrostatic coupling between impurity ions and director fluctuations. Within the vicinity of Sm-A-Sm-C(alpha)(*) transition, the relaxation rate of the slow mode depends linearly on temperature, but with a different slope in each phase. The square root of its intensity shows a clear Curie-Weiss divergence at the phase transition, which is a direct confirmation of the electrostatic coupling mechanism.
authors.affiliation: Research Institute for Materials, University of Nijmegen, 6525 ED Nijmegen, The Netherlands.
authors.forename: A
authors.initials: A
authors.lastname: Rastegar
authors.forename: T
authors.initials: T
authors.lastname: Rasing
authors.forename: I
authors.initials: I
authors.lastname: Musevic
authors.forename: G
authors.initials: G
authors.lastname: Heppke