Intrinsic and extrinsic contribution of dielectric response in PIN-PMN-0.29PT:Mn single crystals by alternating current poling

Abstract

Alternating current poling (ACP) method has emerged as an efficient technique to optimize piezoelectric/dielectric properties of relaxor-PbTiO3 ferroelectric single crystals. The exploration of the dielectric property enhancement in Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-0.29PbTiO3:Mn (PIN-PMN-0.29PT:Mn) single crystals through ACP is of significant importance. However, the underlying property enhancement mechanism of ACP remains controversial. Herein, we conducted a systematic investigation into how the ferroelectric, dielectric, and piezoelectric properties of [001]C-oriented PIN-PMN-0.29PT:Mn crystals are influenced by variations in the cycle, amplitude, and frequency of the AC electric field. The optimal ACP conditions were identified with an electric field amplitude of 10–15 kV/cm, a frequency of 1–10 Hz, and a cycle count of 10–20. Significant improvements in piezoelectric and dielectric properties were observed in ACP samples, with the piezoelectric coefficient and relative permittivity increasing by approximately 20% and 40%, respectively, compared to traditional direct current poling (DCP) samples under optimal conditions. Furthermore, the Rayleigh analysis was employed to quantitatively separate the intrinsic and extrinsic contribution to the dielectric response. The lattice distortion, and intrinsic and extrinsic domain wall motion contributions of the ACP samples increased by nearly 24%, 140%, and 53%, respectively, compared to DCP samples. In order to elucidate the mechanisms underlying property enhancement in ACP samples, we conducted an investigation into the temperature dependence of dielectric properties and explored the characterization of the domain structure under poling conditions by piezoresponse force microscopy for PIN-PMN-0.29PT:Mn single crystals. Our findings revealed that the enhancement in dielectric and piezoelectric properties is attributed to a stronger relaxation characteristic and higher domain wall density, providing novel insights into the mechanism of ACP in ferroelectric single crystals.