Role of Extrinsic Contribution to Temperature Stability of Piezoelectricity for (K,Na)NbO3-(Bi,M)ZrO3 Ceramics with Morphotropic Phase Boundary

Gyoung-Ja Lee,Min-Ku Lee

doi:10.3390/en13081972

Abstract

Temperature stability of dielectric, ferroelectric, and piezoelectric properties were investigated in situ by choosing (K,Na)NbO3-(Bi,K)ZrO3 (KNN-BKZ), (K,Na)NbO3-(Bi,Na,K,Li)ZrO3 (KNN-BNKLZ), and (K,Na)NbO3-(Bi,Li)ZrO3-(KNN-BLZ) as representative ceramics with rhombohedral-orthorhombic-tetragonal (R-O-T), R-T, and enriched T phase boundaries, respectively. The KNN-BNKLZ ceramics, which have an R-T phase boundary, showed the highest piezoelectricity but the worst temperature stability. On the other hand, the KNN-BLZ ceramics, which have an enriched T-phase, were slightly worse in terms of piezoelectricity compared to the R-O-T or R-T phase boundary, but their thermal stability was the best. From analyses of an extrinsic contribution by a difference between the small signal d33 and εrPr and an intensity variation of the (002) and (200) X-ray diffraction peaks for the KNN-based ceramics, it was suggested that increasing the extrinsic contribution in the morphotropic phase boundary region improves the piezoelectricity but decreases the thermal stability.

Highlights

Piezoelectric materials have long been used in sensor or actuator applications because of their ability to convert mechanical energy to electrical energy and vice versa
(Bi,M)ZrO3 (BMZ; M = Na, Li, K, Ag, or combinations thereof) systems have been studied as potential perovskite additives to enhance the piezoelectricity of KNN-based ceramics because they contribute to the formation of a morphotropic phase boundary (MPB), such as a rhombohedral (R)-orthorhombic (O)-tetragonal (T) or R-T phase boundary near room temperature by decreasing the O-T phase transition temperature (TO-T ) and increasing the R-O phase transition temperature (TR-O ) [1,2,3,4,5,6,7,8,9,10,11,12]
R-O-T phase, and KNN-BNKLZ with R-T phase boundary, while the temperature stability of the piezoelectricity decreased in the same order

Summary

Introduction

Piezoelectric materials have long been used in sensor or actuator applications because of their ability to convert mechanical energy to electrical energy and vice versa. (Bi,M)ZrO3 (BMZ; M = Na, Li, K, Ag, or combinations thereof) systems have been studied as potential perovskite additives to enhance the piezoelectricity of KNN-based ceramics because they contribute to the formation of a morphotropic phase boundary (MPB), such as a rhombohedral (R)-orthorhombic (O)-tetragonal (T) or R-T phase boundary near room temperature by decreasing the O-T phase transition temperature (TO-T ) and increasing the R-O phase transition temperature (TR-O ) [1,2,3,4,5,6,7,8,9,10,11,12]. From our recent study [13] investigating the piezoelectricity and thermal aging stability according to the M-composition of 0.955(K,Na)NbO3 -0.045(Bi,M)ZrO3 systems (M: Na, K, (Na,K), (Na,K,Li), (Na,Li)

Methods

Results

Conclusion