Phase structure, electrical properties, and component stability in (1 − x)K0.40Na0.60Nb0.96Sb0.04O3–x(Bi0.92Nd0.08)0.5Na0.5ZrO3 lead-free ceramics

Abstract

(1 − x)K0.40Na0.60Nb0.96Sb0.04O3–x(Bi0.92Nd0.08)0.5Na0.5ZrO3 (KNNS–xBNNZ) lead-free piezoceramics have been synthesized by a conventional solid state sintering method, and the effects of BNNZ content on their phase structure and electrical properties were investigated. The phase boundary of rhombohedral–orthorhombic–tetragonal (R–O–T) has been formed in the composition range of 0.030 ≤ x ≤ 0.040. An optimal comprehensive performance (e.g., d33 ~ 470 ± 10 pC/N, kp ~ 0.50 ± 0.02, TC ~ 283 °C, er ~ 1950, tanδ ~ 0.043, Strain ~ 0.135%, and d33* ~ 450 pm/V) is obtained in the ceramics with x = 0.035. Moreover, a relatively good component stability of piezoelectric properties (d33 ~ 402–470 pC/N, kp ~ 0.485–0.524, Strain ~ 0.133–0.135%, and d33* ~ 443–450 pm/V) is gained in a broad component range from 0.030 to 0.045, which is benefited from the contribution of multiphase boundary (R–O–T, R–T). Therefore, we believe that KNNS–xBNNZ ceramics opens a window for the practical applications in piezoelectric material markets.