Alternate current poling and direct current poling for Pb(Mg_1/3Nb_2/3)O₃–PbTiO₃single crystals

Abstract

We have investigated the effects of alternate current poling (ACP) for four different plates of [100]-oriented (100 – x)Pb(Mg1/3Nb2/3)O3–xPbTiO3 (PMN–xPT, x = 28, 29, 30, 31) single crystals (SCs) obtained from one ingot. A record high piezoelectric coefficient d33 of 3000 pC N–1 for PMN–30PT SCs, and a high free dielectric permittivity of 8900 for PMN–28PT SCs by ACP, 27% higher than those of conventional direct current poling (DCP), were confirmed. X-ray analysis revealed a higher (004) peak intensity and angle of ACP SCs compared to those of DCP. We assume that ACP creates a monoclinic multiphase (MB and MC) and eliminates some portion of the tetragonal phase in SCs. In addition, (004) peak shifts were different between the different PT composition SC samples. This work demonstrates an ACP process with excellent cost performance can offer promising prospects and practical value for PMN–xPT SC piezoelectric transducers.