Liquid-matter relaxor ferroelectrics: from double-well to flatten energy landscapes in polar nematic fluids

Abstract Knowing that the traditional relaxor ferroelectrics stem in crystalline matters, one may ask whether one would stabilize the liquid-matter analogy. The perspective is challenging and may enable a generic design of fluidic and flexible relaxor ferroelectrics. In this report, we unveil a novel polar matter state, dubbed the nematic relaxor ferroelectrics, by artificially introducing random-field polar nanoregions with nematicity into a dielectric nematic environment. We observe clear signatures of relaxors with strong field-induced polarizations, up to 1.1 μC·cm -2 at an ultralow electric field at 5 V·μm -1 , and ultrahigh dielectric permittivity over a broad temperature range. Based on the Landau-Ginzburg-Devonshire theory, we reconstruct free-energy landscapes from electricity-field vs polarization curves. We discover a continuous modification of energy landscapes from a double-well shape to a single-well shape with a broadening energy bottom, corresponding to a shift from nematic ferroelectrics to nematic relaxors with significant polarization fluctuations.