Structure and electrical properties of (0.965 − x)(K0.48Na0.52)NbO3–xBiGaO3–0.035(Bi0.5Na0.5)ZrO3 piezoelectric ceramics

Abstract

(0.965 − x)(K_0.48Na_0.52)NbO₃–xBiGaO₃–0.035(Bi_0.5Na_0.5)ZrO₃ [(0.965 − x)KNN–xBG–BNZ] lead-free piezoelectric ceramics were prepared using normal sintering for improving the piezoelectric properties and temperature stability of KNN-based ceramics. The effects of the BiGaO₃ (BG) content on their phase structure, microstructure, and piezoelectric properties were investigated. Orthorhombic–tetragonal phase coexistence has been found in the ceramics with the composition range of 0 ≤ x ≤ 0.001, and the coexistence of rhombohedral, orthorhombic and tetragonal phases at room temperature was obtained with 0.002 ≤ x ≤ 0.006. Then enhanced piezoelectric properties and a high Curie temperature (e.g., d₃₃ = 312 pC N⁻¹, k_p ∼ 44%, and T_C ∼ 341 °C) were observed. All the results show this system of potassium–sodium niobate-based ceramics demonstrates promising potential in practical applications.