An experimental and theoretical investigation into the reflection spectra of SmC* and SmCA* phases

N W Roberts, H F Gleeson, N Bowring, A Seed, L N Nassif, M R Herbert, J W Goodby, M Hird

Research output: Contribution to journalArticle (Academic Journal)peer-review

11 Citations (Scopus)


Analysis of the reflection spectra of chiral smectic liquid crystal phases is used to provide detailed information on physical parameters, including refractive indices, helicoidal pitch and tilt angle. Numerical models of the antiferroelectric and ferroelectric phases are constructed, based on a 4x4 matrix technique, and a downhill simplex algorithm is employed to fit the model to reflection spectra measured from free-standing films of the materials of interest. The temperature dependence of the refractive indices, dispersion, tilt angle and pitch are reported for three different liquid crystalline materials. The accuracy of the fitting method is around 1%, better than the experimental error, and this is confirmed by comparison of the parameters determined by the fitting program with those measured by independent methods.

Original languageEnglish
Pages (from-to)353-359
Number of pages7
JournalJournal of Materials Chemistry
Issue number2
Publication statusPublished - 2003

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