Helical Columnar Liquid Crystal Exhibiting Both Polarization Retention and Ferroelectric Switching at Room Temperature

Abstract

Abstract Ferroelectric columnar liquid crystals (FCLCs) with switchable bistable axial polarizations are promising candidates for high‐density ferroelectric random‐access memory (FeRAM). However, FCLCs simultaneously exhibiting uniform polarization arrangement and ferroelectric switching at room temperature (RT) remain elusive. Herein, we report an RT‐operable FCLC based on C 3 ‐symmetric star‐shaped mesogen with polar linkers. Two CLCs, 1 and 2 , were synthesized incorporating 1,2,3‐triazole and amide linkers, respectively. 1 undergoes a ferroelectric‐to‐paraelectric transition accompanied by a structural change from helical to a nonhelical columnar phase. Notably, the ferroelectric switching is operable down to RT, with complete retention of its axial macrodipole after removal of the electric field. In contrast, 2 forms only a nonhelical columnar LC phase, displaying paraelectric behavior. The contrasting self‐assembly and dielectric properties are attributed to the differences in the polar unit size. This study demonstrates that the mesogen extension with a bulky 1,2,3‐triazole linker enables the realization of an FCLC operable at RT, offering significant potential for high‐density FeRAM applications.