Phase transitions in a liquid crystal with long-range dipole order

The synthesis and physical properties of a liquid-crystalline material exhibiting the ferrielectric C-gamma*-phase in a broad temperature range are described. The contradictory literature data on this substance are critically reviewed. Dielectric, optical, electrooptic, calorimetric and miscibility studies allowed us to verify the existing data and to establish the complicated phase sequence of the studied substance. The substance possesses many phases specific for materials called antiferroelectric without having the classical antiferroelectric C-a*-phase. The range of existence of the ferrielectric C-gamma*-phase is very broad (about 20degreesC). This feature can be useful in structural investigations of the C-gamma* phase.