Light scattering investigation above the nematic-smectic-A phase transition in binary mixtures of calamitic and bent-core mesogens -: art. no. 031703

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(parallel to)(0) parallel to the layer normal, also decreases rapidly with X. The effect of the dopant on xi(parallel to)(0) is examined in brief theoretically.