TRANSIENT STRIPE PATTERNS OF NEMATICS IN A CONTINUOUSLY ROTATING MAGNETIC-FIELD

We investigate periodically amplified transient stripe textures which are spontaneously formed in the asynchronous reorientation regime of a thin homeotropic NLC layer exposed to an in-plane continuously rotati ng magnetic field. Wavelengths, orientations and ranges of existence o f the stripe texture are determined by means of polarizing microscopy. A theoretical model is given which incorporates backflow coupling and stochastic noise. The model eluciates the hydrodynamic pattern format ion mechanism and describes the time-periodic characteristics of the s tructures in good agreement with the experiment.