Antiferroelectric Liquid Crystal

In the late 1980s, a different arrangement of the molecules in their layer plane was discovered. The phase is known as the antiferroelectric liquid crystal (AFLC) phase. This phase occurs in some materials at a temperature below the FLC phase. These materials, like FLCs, are chiral and possess a spontaneous polarization. The difference is that in the AFLC phase, the director is tilted in opposite direction in alternate layers. This is shown by the animation on the left. The spontaneous polarization is depicted by the blue arrow. The director again is tilted thereby always lying on a theoretical cone.

Click the button labeled, "Cycle through layers" to see the top view of the polarization vector for each layer. You can also see the top view of an individual layer's polarization vector by clicking on that layer. Note how in the AFLC case, in each subsequent layer the director is tilted in the opposite direction and the spontaneous polarization points in the opposite direction. However, the director still precesses around the z axis. For AFLCs the pitch is the distance for the director to precess 180 degrees instead of 360 degrees as for FLCs. This is because due to the opposite tilt in adjacent layers the director also has gone around half of the cone.