dc.contributor.author | VIJ, JAGDISH | en |
dc.contributor.author | FUKUDA, ATSUO | en |
dc.date.accessioned | 2008-06-24T12:36:13Z | |
dc.date.available | 2008-06-24T12:36:13Z | |
dc.date.issued | 2006 | en |
dc.date.submitted | 2006 | en |
dc.identifier.citation | N. Hayashi, T. Kato, A. Kocot, A. Fukuda, J. K. Vij, G. Heppke, S. Kwada, and S. Kondoh, Experimental demonstration, using polarized Raman and infrared spectroscopy that both conventional and de Vries smectic_A phase may exist in smectic liquid crystals with a first-order A-C* transition, Physical Review E, 74, 2006, 051706-1 - 051706-11 | en |
dc.identifier.other | Y | en |
dc.description | PUBLISHED | en |
dc.description.abstract | Two models exist for the orientational distribution of the long molecular axes in smectic-A liquid crystals:
the conventional unimodal distribution and the ?cone-shaped? de Vries distribution. The de Vries hypothesis
provides a plausible picture of how, at a molecular level, a first-order Sm-A to Sm-C* transition may occur,
especially if there is little or no concomitant shrinkage of the layer spacing. This work investigates two
materials with such transitions: C7 and TSiKN65. The azimuthal distribution of in-layer directors is probed
using IR and polarized Raman spectroscopy, which allows us to obtain orientational order parameters. In
C7, we observe a discontinuous change in the order parameter, the magnitude of which is small compared with
the corresponding change in the in-layer director tilt angle . Assuming that the smectic-A liquid crystal is of
the de Vries type, we calculate the required to reproduce the apparent order parameter P2 app, obtained from
IR, by using the true order parameter P2 , obtained from polarized Raman scattering. The results indicate that,
for C7, the tilt angle so calculated is much smaller than that in the Sm-C* angle and hence de Vries behavior
may not be the appropriate explanation in this case. Conversely, we find that TSiKN65 shows a different
behavior to C7, which can be explained in terms of the de Vries concept. Thus, we conclude that either type of
distribution may exist in Sm-A phases which undergo a first-order transition to the Sm-C* phase. We also
discuss the changes in the smectic layer spacing and the orientational order parameters across the Sm-ASm-
C* phase transition, together with changes in birefringence with applied electric field. | en |
dc.description.sponsorship | J.K.V. thanks the Science Foundation
of Ireland for Grant No. SFI 02/In.1/I031 for
funding the research and visit of N.H. to Dublin and
the visiting appointment of A. Kocot. M.J.L. thanks the
European Union for funding under the SAMPA programme
HPRN-CT-2002-00202. Atsuo Fukuda?s research
at Trinity College Dublin was funded by Grant No. SFI
02/W/I02 . | en |
dc.format.extent | 051706-1 | en |
dc.format.extent | 051706-11 | en |
dc.format.mimetype | application/pdf | |
dc.language.iso | en | en |
dc.relation.ispartofseries | Physical Review E | en |
dc.relation.ispartofseries | 74 | en |
dc.rights | Y | en |
dc.subject | Electronic & Electrical Engineering | en |
dc.title | Experimental demonstration, using polarized Raman and infrared spectroscopy that both conventional and de Vries smectic_A phase may exist in smectic liquid crystals with a first-order A-C* transition | en |
dc.type | Journal Article | en |
dc.type.supercollection | scholarly_publications | en |
dc.type.supercollection | refereed_publications | en |
dc.identifier.peoplefinderurl | http://people.tcd.ie/jvij | en |
dc.identifier.peoplefinderurl | http://people.tcd.ie/atsuof | en |
dc.identifier.rssinternalid | 44770 | en |
dc.identifier.doi | http://dx.doi.org/10.1103/PhysRevE.74.051706 | en |
dc.identifier.rssuri | http://scitation.aip.org/getpdf/servlet/GetPDFServlet?filetype=pdf&id=PLEEE8000074000005051706000001&idtype=cvips&prog=normal | en |
dc.contributor.sponsor | Science Foundation Ireland (SFI) | en |
dc.identifier.uri | http://hdl.handle.net/2262/17667 | |