2026-09-20T20:44:54Z https://www.ideals.illinois.edu/oai-pmh

oai:www.ideals.illinois.edu:2142/25614 2023-07-10 col_2142_8859 col_2142_5131 com_2142_8858 com_2142_234 com_2142_5130

McMillan, W.L. Chu, Kung-Chao 2011-07-01T16:32:06Z 2011-07-01T16:32:06Z 10000-01-01 1977 We present here two experiments which measure the static and dynamic pretransition behavior of the nematic-smectic A phase transition of the liquid crystal CBOOA. The first experiment is a conventional Rayleigh light scattering measurement performed with excellent temperature control of the liquid crystal. The second is a novel magneto-optic experiment which uses an external magnetic field to distort the liquid crystal and a sensitive optical interference technique to measure the distortion. Both measurements are performed with millikelvin temperature resolution and yield critical exponents for the elastic constants and the twist viscosity coefficient. These results are inconsistent with the three proposed theories of the critical behavior at least in the simple form in which the theories were first proposed and suggest that further theoretical work is necessary in order to understand this phase transition. A theory of the nonlinear elastic response of liquid crystals near the nematic-smectic A phase transition is also presented. Submitted by Carolyn Mead (cmead2@illinois.edu) on 2011-07-01T16:32:06Z No. of bitstreams: 1 1977_chu.pdf: 2944861 bytes, checksum: 013ef3643f7ed8e815a62018489a1911 (MD5) Made available in DSpace on 2011-07-01T16:32:06Z (GMT). No. of bitstreams: 1 1977_chu.pdf: 2944861 bytes, checksum: 013ef3643f7ed8e815a62018489a1911 (MD5) Previous issue date: 1977 Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Carolyn Mead (cmead2@illinois.edu) on 2011-07-01T16:32:06Z Item is restricted indefinitely. Restriction data tranferred 2014-07-01T11:32:29-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: Thesis Thesis U of I Only 252915 http://hdl.handle.net/2142/25614 en 1977 Kung-Chao Chu pretransition behavior nematic-smectic A phase transition liquid crystal CBOOA Experimental investigations of the pretransition behavior near the nematic-smectic A phase transition Dissertation / Thesis text Physics Physics University of Illinois at Urbana-Champaign Dissertation Ph.D.