LAUSR

Compared with the state-of-the-art Pb(Zr,Ti)O3 ceramics, relaxor-PbTiO3 (PT) based ferroelectric single crystals possess much higher piezoelectricity, thus receiving considerable attention from the ferroelectric community. Recently, it was found that the alternating current electric field poling (AC-poling) could further improve the piezoelectricity of [001]-poled rhombohedral (R) relaxor-PT single crystals. In this work, we investigated the domain structures and electromechanical properties of alternating current electric field poled (AC-poled) relaxor ferroelectric Pb(In1/2Nb1/2)O3–Pb(Mg1/3Nb2/3)O3–PbTiO3 (PIN–PMN–PT) crystals with different orientations and phase structures, including [001]-oriented R PIN–PMN–PT (23/47/30), [011]-oriented R PIN–PMN–PT (23/47/30), and [001]-oriented monoclinic (MC) PIN–PMN–PT (22/44/34) single crystals. We found that the piezoelectric coefficient (d33), free dielectric permittivity (ɛ33T/ɛ0), and clamped dielectric permittivity (ɛ33S/ɛ0) for AC-poled [001]-oriented R PIN–PMN–PT (23/47/30) crystals were improved by 24.4%, 22.6%, and 8.5%, respectively, when compared with the direct current electric field poled (DC-poled) counterparts. This phenomenon is attributed to the increase of domain size according to the observations from polarized light microscopy. Nevertheless, for [011]-poled R PIN–PMN–PT and [001]-poled MC PIN–PMN–PT crystals, the dielectric permittivities and piezoelectric coefficients were decreased a bit by AC-poling, being attributed to the depolarization phenomenon caused by the AC electric field. This work demonstrates that impacts of AC-poling on the properties of ferroelectrics are highly related to the orientation and phase of ferroelectric crystals.