Liquid-matter relaxor ferroelectrics by design

Knowing that traditional relaxor ferroelectrics stem from crystalline materials, one may ask whether they stabilize the liquid-matter analogy. The perspective is challenging and may enable a generic design of fluidic and flexible relaxor ferroelectrics. Here, we unveil a novel polar matter state, dubbed the nematic relaxor ferroelectric, by artificially introducing polar nanoregions with nematicity into a dielectric nematic environment. We observe clear signatures of a nematic relaxor, which exhibits a high field-induced polarization of 1.1 μC·cm−2 at 5 V·μm−1, over a wide temperature range (>30 K). The relaxor demonstrates two regimes: (1) stable relaxor against high electric fields (> 5 V·μm−1) at high temperatures over a 30 K range; (2) relaxor with a field-induced transition to a ferroelectric state at low temperatures. Based on the Landau-Ginzburg-Devonshire theory, we reconstruct free-energy landscapes from the electric field vs polarization curves. We observe a continuous transformation of energy landscapes from a double-well shape to a single-well shape, characterized by a broadening of the energy bottom, corresponding to a shift from nematic ferroelectrics to nematic relaxors with significant polarization fluctuations.