Enhanced piezoelectric properties in potassium-sodium niobate-based ternary ceramics

• Fabricating the ternary (1-x)K0.5Na0.5Nb1-ySbyO3-zSrZrO3-xBi0.5Na0.5HfO3 ceramics by the conventional solid-state reaction method;
• Constructing R-O-T multiphase coexistence in the range of 0.03£x£0.05, 0.04£y£0.06, 0.01£z£0.025;
• Attaining the high d33 (470 ± 5 pC/N) and a relatively high TC (244 °C).

(1 − x)K0.5Na0.5Nb1 − ySbyO3-zSrZrO3-xBi0.5Na0.5HfO3 (KNNS-SZ-BNH) lead-free ceramics were developed by the conventional solid-state reaction method. Effects of the additives (Bi0.5Na0.5HfO3, SrZrO3 and Sb5 +) on their phase structure, microstructure, and electrical properties were investigated. The rhombohedral-orthorhombic-tetragonal (R-O-T) phase boundary can be established in the ceramics with 0.03 ≤ x ≤ 0.05, 0.04 ≤ y ≤ 0.06, and 0.01 ≤ z ≤ 0.025, and then their piezoelectric properties were improved. The ceramics with x = 0.03, y = 0.04 and z = 0.01 possess the optimum piezoelectric properties (d33 = 470 ± 5 pC/N, kp = 0.51 ± 0.02, and TC = 244 °C). We believe that R-O-T multiphase coexistence is mainly responsible for the enhancement of piezoelectric properties.

Enhanced piezoelectric properties (d33 = 470 ± 5 pC/N, kp = 0.51 ± 0.02, TC = 244 °C) were obtained in the KNN-based ceramics with an R-O-T phase boundary driven by Sb5 +, Bi0.5Na0.5HfO3 and SrZrO3.Figure optionsDownload as PowerPoint slide