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arXiv 2502.03319cond-mat.soft
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极性流体中铁电近晶相块体的自发扭转

Spontaneous Twist of Ferroelectric Smectic Blocks in Polar Fluids

Hiroya Nishikawa, Yasushi Okumura, Dennis Kwaria, Atsuko Nihonyanagi, Fumito Araoka

AI总结:

本文通过设计两种非手性分子BOE-NO2和DIOLT,研究铁电向列相的手性基态如何继承到铁电近晶相中,发现具有大偶极矩和位阻基团的BOE-NO2可形成自发扭转的极性近晶相块体。

摘要:

在软物质中,分子的极性取向序可以促进结构手性与铁电性的共存。由具有大偶极矩的非手性棒状分子表现出的铁电向列相(NF)态,是自发结构手性涌现的理想模型。这种手性基态源于去极化效应引起的极化左旋或右旋扭转。相比之下,铁电近晶相态以极性层状结构和较低对称性为特征,其层扭转形变和畴壁形成所涉及的能量显著更高,因此避免了连续扭转的层状结构。在本研究中,我们开发了两种具有不同分子结构但呈现NF-铁电近晶相相序的非手性分子(BOE-NO2和DIOLT)。我们证明,NF的手性基态在BOE-NO2的铁电近晶相中得到继承,该分子具有更大的偶极矩和空间位阻基团,从而触发了扭转极性近晶相块体的形成。

英文摘要:

In soft matter, the polar orientational order of molecules can facilitate the coexistence of structural chirality and ferroelectricity. The ferroelectric nematic (NF) state, exhibited by achiral calamitic molecules with large dipole moments, serves as an ideal model for the emergence of spontaneous structural chirality. This chiral ground state arises from a left- or right-handed twist of polarization due to depolarization effects. In contrast, the ferroelectric smectic state, characterized by a polar lamellar structure with lower symmetry, experiences significantly higher energy associated with layer-twisting deformations and the formation of domain walls, thus avoiding a continuously twisted layered structure. In this study, we develop two types of achiral molecules (BOE-NO2 and DIOLT) that possess different molecular structure but exhibit a NF-ferroelectric smectic phase sequence. We demonstrate that the chiral ground state of NF is inherited in the ferroelectric smectic phases of BOE-NO2, which features larger dipole moments and a steric hindrance moiety, thereby triggering the formation of the twisted polar smectic blocks.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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