A simplified electrohydrodynamic treatment of threshold effects in nematic liquid crystals

The threshold for instability (domain-formation dynamic scattering) was measured for p-azoxyanisole (PAA) and N-(p-methoxybenzylidene(-p-n-butylaniline (MBBA) as a function of sample thickness and conductivity. This parameter was found to be relatively independent of sample thickness and conductivity, having a value in the range of 6 to 8 V for an 8:1 variation in thickness and a 100:1 variation in sample conductivity. These findings were shown to be in agreement with predictions made by a simplified electrohydrodynamic model.