Emergent Ferroelectric Nematic and Heliconical Ferroelectric Nematic States in an Achiral “Straight” Polar Rod Mesogen
Hiroya Nishikawa, Daichi Okada, Dennis Kwaria, Atsuko Nihonyanagi, Motonobu Kuwayama, Manabu Hoshino, Fumito Araoka
Abstract
Abstract Ferroelectric nematic liquid crystals (N F LCs) are distinguished by their remarkable polarization characteristics and diverse physical phenomena, sparking significant interest and excitement within the scientific community. To date, over 150 N F LC molecules are developed; however, there are no reports regarding straight linear polar molecules with a parallel alignment of the permanent dipole moment and the molecular axis. The straight polar mesogen nBOE exhibits an enantiotropic N F phase with a wide temperature window (up to 100 K) despite having a longer alkyl chain (up to n = 6) than the critical alkyl chain length of conventional models. Interestingly, nBOE with a medium‐length alkyl chain displays an exotic phase sequence of N F – HC N F –SmX F during the elimination of positional displacement among adjacent molecules. Furthermore, the reflective color modulation of the HC N F LC over the entire VIS‐NIR spectral regime by ultralow E ‐field (up to 0.14 V µm −1 ) is demonstrated.