| Abstract: | The three refractive indices of a liquid crystal that exhibits lamellar analogues of the three-dimensional isotropic, nematic, and smectic A phases are reported as functions of temperature for the Lam-I and Lam-N phases. The data suggest a number of striking behaviour types. The orientational distribution of the mesogenic moieties becomes more highly peaked in two dimensions on cooling from the Lam-I to the Lam-N phase; the two-dimensional order associated with mesogenic director n in the Lam-N phase is weak; and conformational changes in the side chain result in an increase in the refractive index perpendicular to the lamellae with decreasing temperature in the Lam-N phase. |
