Intrinsic Relaxor‐Like Nature in Single‐Component Polar Nematic Fluids

ABSTRACT Relaxor ferroelectrics (RFEs) exhibit complex heterogeneity of polarity at the nanoscale due to polar nano‐regions (PNRs). They are commonly crystalline‐based materials and widely applied for energy storage, electrostrictive actuators, and electrocaloric devices. In this work, we find a fluid‐based relaxor‐like ferroelectric in single‐component polar nematic fluids, which intrinsically appears as a precursor of emerging ferroelectric fluids with nematic order, dubbed as nematic relaxor‐like ferroelectric (nRFE) liquid crystals. The characteristic relaxor‐like behaviors, including high permittivity, diffuse phase transitions, frequency dispersion in dielectric response, and slim polarization‐electric field hysteresis loop, are identified in all polar nematic fluids experiencing N‐N _F phase transition. These unique dielectric responses would be attributed to the short‐range polar order in the high‐temperature N phase, triggered by strong local dipole‐dipole interaction. The chemical structure influences the thermal range and stability of the relaxor‐like state, the incorporation of thioester linkages proving advantageous for promoting relaxor‐like behavior. Furthermore, the relaxor‐like polar nematic demonstrates impressive performance under low electric field conditions, presenting notable benefits for various electro‐optic devices that necessitate relatively high driving voltages.