1. Liquid crystal mesophases beyond commensurate four-layer periodicity
- Author
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Ron Pindak, Yuji Sasaki, Kenji Ema, Shun Wang, P. Barois, B. K. McCoy, Z. Q. Liu, Cheng-Cher Huang, LiDong Pan, School of Physics and Astronomy [Minneapolis], University of Minnesota [Twin Cities] (UMN), University of Minnesota System-University of Minnesota System, Key Laboratory of Artificial Structures and Quantum Control, Shanghai Jiao Tong University [Shanghai], Department of Physics and Astronomy [Baltimore], Johns Hopkins University (JHU), Department of Mathematics, Physics, and Staitistics [Azusa], Azusa Pacific University, Department of Applied Physics, Graduate School of Engineering, The University of Tokyo, Centre de recherches Paul Pascal (CRPP), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Photon Sciences Directorate, Brookhaven National Laboratory [Upton, NY] (BNL), U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY)-U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY), Contract N° DE-AC02-98CH10886, School of Physics and Astronomy, University of Minnesota [Minneapolis], Johns Hopkins University ( JHU ), Department of Physics and Astronomy, St. Cloud State University, Department of Mathematics and Physics, Azusa Pacific University, Centre de recherches Paul Pascal ( CRPP ), Centre National de la Recherche Scientifique ( CNRS ), and Brookhaven National Laboratory
- Subjects
Diffraction ,Materials science ,Theoretical models ,02 engineering and technology ,01 natural sciences ,resonant X-ray diffraction ,SmC∗ ,SmC∗d6 ,[ CHIM.CRIS ] Chemical Sciences/Cristallography ,null-transmission ellipsometry ,Liquid crystal ,Ellipsometry ,Phase (matter) ,Physical phenomena ,0103 physical sciences ,[CHIM.CRIS]Chemical Sciences/Cristallography ,General Materials Science ,010306 general physics ,Mesophase ,General Chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,variant phases ,Crystallography ,Chemical physics ,0210 nano-technology ,Ternary operation - Abstract
International audience; For more than one decade, SmC∗d4, SmC∗d3, andSmC∗ A were the only three confirmed commensurate SmC* variant phases with periodicities less than or equal four layers. In 2006, employing ellipsometry and resonant X-ray diffraction (RXRD), our research team first discovered a new liquid crystal mesophase having a six-layer periodicity in one ternary mixture which includes one sulfur-containing compound. From our ellipsometric results, this phase showed antiferroelectric-like optical response. This novel discovery inspired renewed interest to search for liquid crystal mesophases with commensurateperiodicities greater than four layers. Soon after, another mesophase having a six-layer structure and showing a ferrielectric-like dielectric response, instead, was uncovered by RXRD measurements on a different binary mixture which has one bromine-containing compound. Meanwhile mesophases having a 5-, 8-, 12- or 15-layer periodicity were reported. However, numerous questions remain to be addressed associated with these unusual reported phases. Theoretical models giving rise to mesophases with periodicities greater than four layers have been developed; but, to date, none of them haveprovided satisfactory explanations of all the physical phenomena related to the mesophases exhibiting a six-layer structure. Moreover, the question “what is the source of long-range interactions between liquid-like smectic layers, which are responsible for establishing mesophases with long periodicities and mean-field behavior of the smectic-A–smectic-C transition?” remains unanswered for more than three decades.
- Published
- 2015