Enhanced temperature stability in the O–T phase boundary of (K, Na)NbO3‐based ceramics.

In order to obtain excellent electrical properties and its temperature stability of KNN‐based ceramics to meet the practical applications, a new lead‐free material system of (1−x)K0.5Na0.5Nb0.96Sb0.04O3‐xBi0.5Na0.5Zr0.8Sn0.2O3 (KNNS‐xBNZS, 0 ≤ x ≤ 0.060) was designed, and the enhanced electrical properties (eg, d33 ~ 465 pC/N, εr ~ 3318, Suni ~ 0.133%) is obtained in the ceramics with x = 0.04. The physical origin of enhanced electric properties should be ascribed to the phase instability of R‐T, resulting in a low‐energy barrier, which can greatly facilitate the polarization switching. Moreover, the temperature stable of piezoelectric constant (d33 or d33*) is measured by three distinctive methods in different phase boundaries (O, O‐T, R‐T) at the temperature range 20°C‐180°C, revealing that the O‐T phase boundary has a relatively good temperature stability. A mode is used to show how to effectively modified the piezoelectric constant (d33 or d33*) and its temperature stability, we believe that such a strategy may further improve the temperature stability of d33 or d33* value in KNN‐based ceramics. [ABSTRACT FROM AUTHOR]