Dielectric Relaxations in a Short Pitch Ferroelectric Liquid Crystal

Abstract

Dielectric measurements in the frequency range 100 Hz to 100 kHz have been carried out in a short pitch ferroelectric liquid crystal mixture FLC-6430 (Hoffmann-La-Roche) in the SmC* phase aligned in planar orientation. The effects of temperature, frequency and bias voltage on the dielectric properties of this material have been investigated. The relaxation frequency fr, distribution parameter α and the dielectric strength ε _s , have been determined. The calculated values were found to be ∼0.59 kHz, 0.134 and 427.77 respectively for fr, α and ε _s at 45°C. A constant DC bias of 0.13 V/μm applied to the sample partially suppresses the Goldstone mode.

Key Words:

• Dielectric relaxation
• ferroelectric liquid crystal mixture
• short pitch
• Goldstone mode
• soft mode