Zobrazeno 1 - 10
of 65
pro vyhledávání: '"S, Pirkl"'
Autor:
S. Pirkl, Patrick Oswald
Publikováno v:
Physical review. E, Statistical, nonlinear, and soft matter physics. 89(2)
We study the Lehmann rotation of the cholesteric helix in droplets of the liquid crystal N-($p$-methoxybenzilidene)-$p$-butylaniline doped with a small amount of the chiral molecule R811 when they are subjected to a temperature gradient. We show that
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::2486f902a5c0e131e5e88d57f6123764
https://pubmed.ncbi.nlm.nih.gov/25353491
https://pubmed.ncbi.nlm.nih.gov/25353491
Publikováno v:
Liquid Crystals. 28:299-306
We review the different dynamical patterns that cholesteric fingers of the first type (CF-1) and of the second type (CF-2) form in an a.c. electric field near the coexistence line with the homeotropic nematic phase. Videomicroscopy and computer image
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::13f068fa83ee71d39cbfe7f85bcfdb91
https://doi.org/10.1080/02678290010007233
https://doi.org/10.1080/02678290010007233
Publikováno v:
Physics Reports. 337:67-96
In a cholesteric liquid crystal, the rod-like molecules present a helical arrangement in a single direction. The pitch of the helix at equilibrium can be continuously changed by dissolving a chiral molecule in a nematic phase. This helix can also be
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::a50e6a5dd579019efac3bd200fc7e0aa
https://doi.org/10.1016/s0370-1573(00)00056-9
https://doi.org/10.1016/s0370-1573(00)00056-9
Publikováno v:
Physical Review E. 60:2990-2993
We show that the drift velocity of the cholesteric fingers of the second species in ac electric field strongly depends on the conductivity of the liquid crystal chosen and exponentially vanishes above a cutoff frequency we found to be equal (within a
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::d43c73513cf7a401703c37456bd13f2f
https://doi.org/10.1103/physreve.60.2990
https://doi.org/10.1103/physreve.60.2990
Publikováno v:
Physical Review E. 57:3038-3049
We study the nucleation of cholesteric fingers in directional growth when a cholesteric phase of positive dielectric anisotropy grows into its isotropic liquid. The experiment is performed in homeotropic anchoring and in electric field near the coexi
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::af6cbd07540805b473fe734244b32b33
https://doi.org/10.1103/physreve.57.3038
https://doi.org/10.1103/physreve.57.3038
Publikováno v:
Liquid Crystals. 21:893-901
We have observed an arch-texture in cholesteric liquid crystals sandwiched between two glass plates making a small wedge angle. The anchoring is homeotropic on one plate and planar on the opposite one. This texture is locally periodic and composed of
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::398e45599a99cf66f3bdf0e47f91f715
https://doi.org/10.1080/02678299608032907
https://doi.org/10.1080/02678299608032907
Autor:
Patrick Oswald, S. Pirkl
Publikováno v:
Journal de Physique II. 6:355-373
We first show how to make a finger of the second species from a bubble domain in a frustrated cholesteric liquid crystal in an A-C- electric field. Two scenarios are possible, depending on the applied voltage: either the finger forms a single spiral,
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::51c863d5e0bd6ab2683210401ce0cf2b
https://doi.org/10.1051/jp2:1996187
https://doi.org/10.1051/jp2:1996187
Publikováno v:
Liquid Crystals. 16:203-221
In a previous article, we proposed a model to explain the unwinding transition in an electric field of a frustrated cholesteric liquid crystal sandwiched between two glass plates imposing a homeotropic anchoring. We found that three distinct solution
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::6c0d9b38e416f1eb66d360aa466ba2b9
https://doi.org/10.1080/02678299408029147
https://doi.org/10.1080/02678299408029147
Publikováno v:
Liquid Crystals. 13:413-425
The nucleation of bubble domains in homeotropic samples of a dielectrically positive cholesteric liquid crystal is described. These domains are found to be more stable in an electric field than the rectilinear double-twisted fingers. The electric fie
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::91c59d88ee3bb8fcf23e6d0c40ca3e37
https://doi.org/10.1080/02678299308026314
https://doi.org/10.1080/02678299308026314
Autor:
S. Pirkl
Publikováno v:
Crystal Research and Technology. 28:1027-1038
Behaviour of a chiral nematic mixture with a negative dielectric anisotropy was studied between two electrodes with homeotropic anchoring in the presence of an a.c. electric field. By changing the sample thickness d and field strength E at constant c
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::9bffa9d8691ca3076856c9a1fe691bbf
https://doi.org/10.1002/crat.2170280729
https://doi.org/10.1002/crat.2170280729