Improving the piezoelectric properties of Pb(Ni, Nb)O3-Pb(Hf, Ti)O3 ceramics through Nd2O3 addition

Abstract

High-performance piezoelectric materials, whose displacement is sensitive to an external field and vice versa, are constantly required in electromechanical applications. Here, we introduce Nd3+ ions into 0.49Pb(Nb2/3Ni1/3)O3-0.51Pb(Hf0.3Ti0.7)O3 (PNN-PHT) ceramics via the solid-state method. By constructing a ferroelectric system in the morphotropic phase boundary region and exploiting the synergistic effect of polar nanoregions and an enhanced local structural heterogeneity, excellent piezoelectricity and dielectric properties are obtained. The optimized piezoelectric coefficient d33, dielectric constant ε33, electromechanical coupling factor kp, and dielectric loss tanδ are 1125 pC/N, 8667, 0.66 %, and 1.94 %, respectively. The Vogel-Fulcher law and relaxation analysis were adopted to understand the origin of the high piezoelectricity. The Rayleigh analysis method was used to study the intrinsic and extrinsic contributions to the piezoelectricity of the Nd-doped PNN-PHT ceramics, the extrinsic contribution was found to be up to 19 % in the optimal region (PNN-PHT + 0.4 at. % Nd2O3). Moreover, according to in-situ ferroelectric measurements and fatigue measurements, the PNN-PHT + 0.4 at. % Nd2O3 ceramic exhibits excellent fatigue resistance and stable piezoelectric behavior at 60 ℃. This work provides an approach to realize high-performance piezoelectric ceramics with good electromechanical stability under external condition, which is expected to expand the range of application of piezoelectric materials, e.g., for transducers.