title: Molecular dynamics of a binary mixture of twist-bend nematic liquid crystal dimers studied by dielectric spectroscopy.
abstract: We report a comprehensive dielectric characterization of a liquid crystalline binary mixture composed of the symmetric mesogenic dimer CB7CB and the nonsymmetric mesogenic dimer FFO9OCB. In addition to the high-temperature nematic phase, such a binary mixture shows a twist-bend nematic phase at room temperature which readily vitrifies on slow cooling. Changes in the conformational distribution of the dimers are reflected in the dielectric permittivity and successfully analyzed by means of an appropriate theoretical model. It is shown that the dielectric spectra of the mixture reflect the different molecular dipole properties of the components, resembling in the present case the characteristic dielectric spectra of nonsymmetric dimers. Comparison of the nematic and twist-bend nematic phases reveals that molecular dynamics are similar despite the difference in the molecular environment.
authors.affiliation: Departamento de Física Aplicada II, Facultad de Ciencia y Tecnología, Universidad del País Vasco, Apartado 644, E-48080 Bilbao, Spain.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Robles-Hernández
authors.affiliation: Departamento de Física Aplicada II, Facultad de Ciencia y Tecnología, Universidad del País Vasco, Apartado 644, E-48080 Bilbao, Spain.|Otto-von-Guericke Universitat Magdeburg, Institute for Experimental Physics, ANP, 39106 Magdeburg, Germany.
authors.forename: Nerea
authors.initials: N
authors.lastname: Sebastián
authors.affiliation: Grup de Propietas Físiques dels Materials (GRPFM), Departament de Física, E.T.S.E.I.B. Universitat Politècnica de Catalunya, Diagonal 647, E-08028 Barcelona, Spain.
authors.forename: Josep
authors.initials: J
authors.lastname: Salud
authors.affiliation: Grup de Propietas Físiques dels Materials (GRPFM), Departament de Física, E.T.S.E.I.B. Universitat Politècnica de Catalunya, Diagonal 647, E-08028 Barcelona, Spain.
authors.forename: Sergio
authors.initials: S
authors.lastname: Diez-Berart
authors.affiliation: School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, United Kingdom.
authors.forename: David A
authors.initials: DA
authors.lastname: Dunmur
authors.affiliation: Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom.
authors.forename: Geoffrey R
authors.initials: GR
authors.lastname: Luckhurst
authors.affiliation: Grup de Propietas Físiques dels Materials (GRPFM), Departament de Física, E.T.S.E.I.B. Universitat Politècnica de Catalunya, Diagonal 647, E-08028 Barcelona, Spain.
authors.forename: David O
authors.initials: DO
authors.lastname: López
authors.affiliation: Departamento de Física Aplicada II, Facultad de Ciencia y Tecnología, Universidad del País Vasco, Apartado 644, E-48080 Bilbao, Spain.
authors.forename: M Rosario
authors.initials: MR
authors.lastname: de la Fuente