Defect Chemistry and Structural Heterogeneity Induced High Piezoelectric Performance of Nb 2 O 5 -Doped x PNN-(1 – x )PZ 0.49– y T 0.51+ y Solid Solutions near the Morphotropic Phase Boundary

作者：Yiyi Wang, Jing Shi, Fangyuan Zhu, Chenxi Liu, Liting Wang, Changbai Long, Wenchao Tian, Laijun Liu, Tao Zhang, Dawei Yi, Xiao Liu · 发表于：Inorganic Chemistry · 年份：2025 · DOI：10.1021/acs.inorgchem.5c04063 · 被引用次数：3 · 研究领域：Ferroelectric and Piezoelectric Materials、Acoustic Wave Resonator Technologies、Microwave Dielectric Ceramics Synthesis

In the field of actuators based on piezoelectric ceramics, it is extremely important to simultaneously achieve high piezoelectric coefficients ( d 33 ) and electromechanical coupling factors ( k p ). This study investigates ternary x PbNi 1/3 Nb 2/3 O 3 -(1 – x )PbZr 0.49– y Ti 0.51+ y O 3 (PNN–PZT) piezoelectric solid solutions around the morphotropic phase boundary systematically. The anomalous polarization and conduction mechanisms of Nb 2 O 5 doping in enhancing the piezoelectric performance are clarified by revealing the synergistic effects of defect chemistry and structural heterogeneity. Prominent integrated piezoelectric properties ( d 33 = 796 pC/N, k p = 0.82, and T c = 169 °C) are obtained by introducing a moderate Nb 2 O 5 donor dopant associated with preferential occupancy and a nonmonotonic phase transition. The distortion of the BO 6 octahedra and the formation of localized nanodomain structures contribute to the softened B–O bond repulsion and promote domain wall motion. They are significantly affected by the interaction between the oxygen vacancy migration capacity and the generated lead vacancies, which are disclosed by complex impedance. The intrinsic and extrinsic contributions originated from lattice distortion and domain wall activity that facilitate the piezoelectric response are further learned by the domain structure and Rayleigh analyses. This study provides a new paradigm for designing high performance of d 33 and k p in relaxor ferroelectrics throu...