  Recent experimental realization of ferroelectric nematic liquid crystalline
phases stimulated material development and numerous experimental studies of
these new phases, guided by their fundamental and applicative interest. In this
Perspective, we give an overview of this emerging field by linking history and
theoretical predictions to a general outlook of the development and properties
of the materials exhibiting ferroelectric nematic phases. We will highlight the
most relevant observations up-to-date, e.g., giant dielectric permittivity
values, polarization values an order of magnitude larger than in classical
ferroelectric liquid crystals, and nonlinear optical coefficients comparable to
several ferroelectric solid materials. Key observations of anchoring and
electro-optic behavior will also be examined. The collected contributions lead
to a final discussion on open challenges in materials development, theoretical
description, experimental explorations, and possible applications of the
ferroelectric phases.
