Ferroelectric domain-wall motions associated with local proton rearrangement and collective proton relay have been revealed in hydrogen-bonded organic ferroelectrics, Phz-H${}_2$ca [phenazine (Phz)-chloranilic-acid (H${}_2$ca)], through dielectric measurements and piezoresponse force microscopy. The domain wall (DW) and thus protons therein are found to be so mobile as to migrate spontaneously, and this feature can be accounted for by the characteristic proton dynamics emergent in this material. Our findings indicate that incomplete proton transfer is a key to a mobile ferroelectric DW in hydrogen-bonded ferroelectrics.

• Received 15 February 2012

DOI:https://doi.org/10.1103/PhysRevB.85.220101