Mechanical-Induced Polarization Switching in Relaxor Ferroelectric Single Crystals

Control of coupling between electric and elastic orders in ferroelectric bulks is vital to understand their nature and enrich the multifunctionality of polarization manipulation applied in domain-based electronic devices such as ferroelectric memories and data storage ones. Herein taking (1-x%)Pb(Mg1/3Nb2/3)O3-x%PbTiO3 (PMN-x%PT, x = 32, 40) as prototypes, we demonstrate the less explored mechanical switching in relaxor ferroelectric single crystals using scanning probe microscopy. Low mechanical forces can induce metastable and electrically erasable polarization reversal clearly from electrical-created bipolar domains around 180° domain wall in monoclinic PMN-32%PT and inside c+ domain in tetragonal PMN-40%PT. The mechanical switching evolutions show force-/time-dependence and time-force equivalence. The time-dependent mechanical switching behavior is stemmed from the participation and contribution of polar nanoregions. Flexoelectricity and bulk Vegard strain effect can account for the mechanical switchi...