title: Hydrogen-bonded silica gels dispersed in a smectic liquid crystal: a random field XY system.
abstract: The effect on the nematic to smectic-A transition in octylcyanobiphenyl (8CB) due to dispersions of hydrogen-bonded silica (aerosil) particles is characterized with high-resolution x-ray scattering. The particles form weak gels in 8CB creating a quenched disorder that replaces the transition with the growth of short-range smectic correlations. The correlations include thermal critical fluctuations that dominate at high temperatures and a second contribution that quantitatively matches the static fluctuations of a random field system and becomes important at low temperatures.
authors.affiliation: Center for Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: S
authors.initials: S
authors.lastname: Park
authors.forename: R L
authors.initials: RL
authors.lastname: Leheny
authors.forename: R J
authors.initials: RJ
authors.lastname: Birgeneau
authors.forename: J-L
authors.initials: JL
authors.lastname: Gallani
authors.forename: C W
authors.initials: CW
authors.lastname: Garland
authors.forename: G S
authors.initials: GS
authors.lastname: Iannacchione