X-ray, Dielectric and High Pressure Studies on a Compound Exhibiting Ferro-, Ferri- and Antiferroelectric Smectic Phases

Abstract

We report X-ray layer spacing, dielectric constant and high pressure measurements on a compound that exhibits the following sequence of phase transitions: smectic A-ferroelectric smectic C*-ferrielectric smectic C _y*-antiferroelectric smectic C_A *-hexatic antiferroelectric smectic I_A *-crystal K. The pressure-temperature diagram shows two three-phase meeting points, which are topologically consistent with critical end points, and reentrant behavior of the C* and C* phases as the pressure is varied at constant temperature.

Key Words:

• Ferroelectric
• ferrielectric
• antiferroelectric
• smectics
• X-ray
• dielectric constant
• high pressure studies
• pressure temperature phase diagram
• critical end point