Ultrafast dynamics of nematic liquid crystals in the isotropic phase

John Joseph Stankus; Renato Torre; Scott R. Greenfield; A. Sengupta; Michael D. Fayer

doi:10.1117/12.147059

17 June 1993 Ultrafast dynamics of nematic liquid crystals in the isotropic phase

John Joseph Stankus, Renato Torre, Scott R. Greenfield, A. Sengupta, Michael D. Fayer

Proceedings Volume 1861, Ultrafast Pulse Generation and Spectroscopy; (1993) https://doi.org/10.1117/12.147059
Event: OE/LASE'93: Optics, Electro-Optics, and Laser Applications in Scienceand Engineering, 1993, Los Angeles, CA, United States

Abstract

Measurements of orientational relaxation over 6 decades in time have been made on the liquid crystal Methoxy Benzylidene butyl aniline (MBBA) using a Transient Grating Optical Kerr effect experiment (TG-OKE). The Slower dynamics have been shown to fit to Landau-de Gennes modified Debye Stoke Einstein Hydrodynamic equation. The faster dynamics show a power law behavior that is temperature independent for 43 degree(s) above the nematic-isotropic phase transition. The slower dynamics deviate from Landau-de Gennes behavior at the same temperature that the faster dynamics become temperature dependent. This is attributed to the domain size, the factor controlling the slow decay, becoming small enough that the local structure is disturbed. Two possible sets of processes are proposed for the power law dependence of the faster dynamics. A parallel process, the Forster direct transfer model, where there is a distribution of potential surfaces for the system to propagate along and the serial process (or Hierarchically constrained dynamics model) where some degrees of freedom are suppressed unless other degrees of freedom are in particular states. These results are compared to earlier work on pentylcyanobiphenyl(5CB). The same behavior is seen in both 5CB and MBBA.

Citation Download Citation

John Joseph Stankus, Renato Torre, Scott R. Greenfield, A. Sengupta, and Michael D. Fayer "Ultrafast dynamics of nematic liquid crystals in the isotropic phase", Proc. SPIE 1861, Ultrafast Pulse Generation and Spectroscopy, (17 June 1993); https://doi.org/10.1117/12.147059

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members: $17.00

Non-members: $21.00 ADD TO CART

PROCEEDINGS
12 PAGES

DOWNLOAD PAPER SAVE TO MY LIBRARY

GET CITATION

RIGHTS & PERMISSIONS

Get copyright permission Get copyright permission on Copyright Marketplace

KEYWORDS

Liquid crystals

Liquids

Temperature metrology

Molecules

Spectroscopy

Kerr effect

Motion models

Show All Keywords

Keywords/Phrases

Search In:

Publication Years