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

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.