Physics

Organic chemistry

Flexoelectricity

Optics

Astronomy

Liquid crystal

Dielectric

Physical chemistry

Chemical physics

Chemistry

Materials science

Polarization (electrochemistry)

Condensed matter physics

Polar

Phase (matter)

Anisotropy

Optoelectronics

Ferroelectricity

Phase diagram

Giant

Ferroelectricity is a property with spontaneous polarization, which is of paramount importance in modern electrooptic applications. Yet, its observations are mostly limited to solids or chiral smectic C liquid crystals with nearly no fluidity. The fluidic ferroelectrics, called ferroelectric nematics, have recently become available by incorporating strong polarity into the apolar liquid crystalline orientational field. Here, we present a rational principle for designing the ferroelectric materials and controlling their phase behaviors. We reveal that, while the apolar nematic order with the second-rank tensor originates from the shape anisotropy in the apolar nematic state, the polarization field serves as an additional mechanism for stabilizing polar nematic orders. Based on a comprehensive set of examinations and machine-learningdriven analyses for about 150 chemically distinct polar rod-shaped molecules, we uncover that the interplay between the shape anisotropy and polarization field gives rise to a diversification of the polar liquid crystal behaviors. The strategy offers much broader design flexibility and may facilitate the development of future polar functional liquid crystals.

General phase-structure relationship in polar rod-shaped liquid crystals: Importance of shape anisotropy and dipolar strength