Surface and finite-size effects on N−Sm−A−Sm−C phase transitions in free-standing films
| Autor: | M. S. S. Pereira, E. J. L. de Oliveira, D. C. S. de Melo, I. N. de Oliveira, Luiz Roberto Evangelista |
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| Rok vydání: | 2020 |
| Předmět: |
Surface (mathematics)
Phase transition Materials science Condensed matter physics Transition temperature Order (ring theory) Molecular orbital theory 01 natural sciences Thermotropic crystal 010305 fluids & plasmas Condensed Matter::Soft Condensed Matter Liquid crystal Phase (matter) 0103 physical sciences 010306 general physics |
| Zdroj: | Physical Review E. 102 |
| ISSN: | 2470-0053 2470-0045 |
| DOI: | 10.1103/physreve.102.022702 |
| Popis: | The present study is devoted to the investigation of surface anchoring and finite-size effects on nematic--smectic-$A$--smectic-$C$ $(N\ensuremath{-}\mathrm{Sm}\text{\ensuremath{-}}A\ensuremath{-}\mathrm{Sm}\text{\ensuremath{-}}C)$ phase transitions in free-standing films. Using an extended version of the molecular theory for smectic-$C$ liquid crystals, we analyze how surface anchoring and film thickness affect the thermal behavior of the order parameters in free-standing smectic films. In particular, we determine how the transition temperature depends on the surface ordering and film thickness. We show that the additional orientational order imposed by the surface anchoring may lead to a stabilization of order parameters in central layers, thus modifying the nature of the phase transitions. We compare our results with experimental findings for typical thermotropic compounds presenting a $N\ensuremath{-}\mathrm{Sm}\text{\ensuremath{-}}A\ensuremath{-}\mathrm{Sm}\text{\ensuremath{-}}C$ phase sequence. |
| Databáze: | OpenAIRE |
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