Light scattering investigation above the nematic-smectic-A phase transition in binary mixtures of calamitic and bent-core mesogens.
Quasielastic light scattering measurements were performed in the nematic phase of mixtures consisting of the calamitic mesogen 8OCB doped with small concentrations of the bent-core molecule P-7PIMB. It was found that the regular part of the bend elastic constant decreases strongly with dopant concentration X. Close to the nematic-smectic-A phase transition temperature, the divergent part of the bend elastic constant, which is proportional to the bare correlation length xi(0)(||) parallel to the layer normal, also decreases rapidly with X. The effect of the dopant on xi(0)(||) is examined in brief theoretically.
Dodge
Mohammad Reza
MR
Department of Physics, Case Western Reserve University, Cleveland, Ohio 44106-7079, USA.
Petschek
Rolfe G
RG
Rosenblatt
Charles
C
Neubert
Mary E
ME
Walsh
Margaret E
ME