Abstract
Effects of electric fields on the ultrasonic attenuation in nematic and cholesteric liquid crystals are investigated. When ultrasound is applied parallel to the electric field, the change of the attenuation in the nematic liquid crystal MBBA first decreases with the increase of the electric field intensity as it is small, then begins to increase above a certain intensity, and finally saturates. When the sound is applied perpendicular to the electric field, the change is in the opposite direction as MBBA is electrically negative. On the other hand, for the nematic mixture which is electrically positive, the change of the attenuation varies monotonously with the electric field intensity and reaches saturation. The phenomenon can be explained by the molecular alignment due to the electric field together with the ultrasonic scattering due to the density fluctuation in the liquid crystal caused by the ion injection. The attenuation characteristics of the cholesteric liquid crystals COC, CO, and cholesteric mixture are also measured, whose magnitude of the attenuation is less than a quarter of that of the nematic liquid crystals.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
