Local structural heterogeneity induced large flexoelectricity in Sm-doped PMN–PT ceramics

Abstract

The recently discovered large flexoelectricity in relaxor ferroelectrics has rekindled considerable research interest. In this paper, several Sm-doped Pb(Mg2/3Nb1/3)O3–xPbTiO3 (PMN–xPT) ferroelectric ceramics were prepared and the relationship between flexoelectricity and PT content was systematically investigated. The largest flexoelectric response (∼550 μC/m) was observed in the Sm-doped PMN–32PT ceramic, which should be accounted for in the reorientation of the polar nanoregions. At room temperature, the flexoelectric response of Sm-doped PMN–32PT ceramic is an order of magnitude higher than that of the parent PMN–PT ceramics and even 50% higher than that of Bi–PMN–32PT ceramic (∼300 μC/m). Such a big increment is directly related to the greater local structural heterogeneity caused by Sm3+ ions into PMN–PT. Therefore, the result presented in this paper verifies that introducing local structural heterogeneity is a feasible approach to achieve ultrahigh flexoelectricity.

Composition dependent phase structure, dielectric and electrostrain properties in (Sr0.7Bi0.2□0.1)TiO3–PbTiO3–Bi(Mg0.5Ti0.5)O3 systems

“…, where C is Curie-Weiss constant. The parameter γ reveals diffuse phase transition character in a material: the system is an ideal normal ferroelectric as γ = 1 and an ideal relaxors as γ = 2 [35]. As shown in figure 3(i), ∆T relax and γ gradually increases with addition of BMT content, which indicates that relaxor degree is enhanced [36].…”

The emancipation of flexoelectricity

“…Possible approaches of enhancing flexoelectric properties are discussed in polymers, 51,52,44,53 ceramics, [54][55][56][57] ferroelectrics, [58][59][60][61][62] and two-dimensional (2D) materials. 63,62 There is also an intriguing proposal regarding flexoelectricity in metals.…”