| Summary: | Potential ferroelectricity in charge-transfer organic materials is often masked by the intrinsic conductivity. Here, we report the compelling evidence of ferroelectricity in organic p-conjugated meta-nitroaniline (m-NA) crystals as shown by the local electromechanical measurements using the piezoresponse force microscopy (PFM) technique. m-NA is a charge-transfer molecular material with the exceptional optical non-linearity and perceptible conductivity along the crystallographic polar axis. While standard Sawyer-Tower measurements revealed an apparently lossydielectric hysteresis, The PFM switching spectroscopy indicated clear ferroelectric behaviour in this technologically important multifunctional material. Further study of the pyroelectric properties in m-NA crystals confirmed their high spontaneous polarization of 18 microC/cm2 at room temperature, comparable to the best known organic ferroelectrics.
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