Structure of blue phase II in a cholesteric-nematic mixture

Abstract
Polarized Bragg-scattering measurements using visible light have been used to determine the structure of the blue phases of cholesteric liquid crystals. Observations of the third Bragg peak (in order of decreasing wavelength) in CB15-E9 mixtures [chiral 4-cyano-4′-(2-methyl)butylbiphenyl (CB15) and a proprietary mixture of nematic biphenyl compounds (E9) from British Drug House] reveal that, for these mixtures, blue phase II has a body-centered-cubic structure.