A SIMPLE AND RELIABLE METHOD FOR MEASURING THE LIQUID-CRYSTAL ANCHORING STRENGTH COEFFICIENT

By measuring the electric Freedericksz transition threshold in a wedge d capacitance cell, we have developed a simple method for determining the anchoring strength coefficient for tilt of the director relative t o the substrate normal. This technique requires neither a knowledge of the absolute cell thickness nor a knowledge of the optical birefringe nce. Moreover, it applies to both the homeotropic orientation for Delt a(chi) < 0, and to the planar orientation for Delta(chi) > 0, where De lta(chi) is the dielectric susceptibility anisotropy.