Comparative dielectric investigations on samples consisting of fluorinated bent core molecules

Abstract

Dielectric measurements on four samples composed of bent-shaped molecules with the same basic structure were carried out. They differ only in the position of one fluorine atom in the central core. Two relaxation ranges were detected: the fast reorientation about the long axes and a slow collective process. In three cases, evidence for a positive dipole correlation in the isotropic phase near to the transition to the B₂2 phase was found. All samples show a tendency to give a glass transition. The dielectric constants are discussed in relation to the position of the fluorine atoms.