Optical response of nematic droplets in a polymer matrix to a strong pulsed magnetic field

Abstract

A change in the optical transmission of an ordered single-layer ensemble of nematic liquid crystal (NLC) droplets of 4-n-pentyl-4′-cyanobiphenyl (5CB) in a poly(vinyl butyral) (PVB) matrix in response to a magnetic field pulse with an amplitude of H = 9 × 106 A/m was observed. Since the leading pulse front duration (τonH = 5 ms) significantly exceeded the theoretically calculated NLC response time (τonLC = 0.8 ms), the dynamics of transformations of the NLC director orientation and the optical response were analogous to those in the case of a stationary or slowly varying magnetic field. In contrast, the field decay time (τoffH = 25 ms) was much shorter than the NLC relaxation time (τoffLC = 300 ms) and, hence, the trailing front of the optical response was not influenced by the oscillatory character of the magnetic field decay during capacitor discharge via an RL chain.