BS in Physics
In this experiment we used dielectric spectroscopy to observe the dielectric response of two De Vries liquid crystals; W-652 and W-751. A frequency sweep was run for each sample with various electric fields applied using an AC current. The samples demonstrated opposing effects at the SmA to SmC as the electric fields were increased. The W-751 showed an increased response with an increased electric field and a resonance peak in high frequencies that shifted through the transition, although there were no clear results in the low frequency range so there is no conclusive trend. The W- 652 sample opposed the expected results of a DeVries liquid crystal and decreased response with an increased voltage. This effect is a unique property of the sample and further analysis is out of the scope of this experiment.