Electromechanical properties of paper‐derived potassium sodium niobate piezoelectric ceramics

Abstract

The small‐signal dielectric and piezoelectric coefficients of paper‐derived sodium potassium niobate, K0.5Na0.5NbO3 (KNN), were compared with those of conventionally prepared samples. Results show similar functional properties of paper‐derived KNN without significantly decreasing the small‐signal piezoelectric coefficient. The structure and microstructure analysis of conventional KNN and paper‐derived KNN did not reveal any significant difference in the crystal structure and grain size. However, the temperature‐dependent inter‐ferroelectric phase transition temperature estimated from the temperature‐dependent dielectric permittivity data revealed a decrease of approximately 18°C for the paper‐derived KNN and is possibly associated with the structural and microstructural defects. This work indicates that optimizing suspension chemistry and sintering conditions will be critical to enhance the functional response of paper‐derived KNN further. Moreover, paper‐derived ceramic processing, a novel and cost‐effective additive manufacturing technology, can be potentially used to fabricate other electroceramics with a wide range of porosities and sizes as well as complex geometries and multilayer structures.

Influence of temperature-induced A-site cation redistribution on the functional properties of A-site complex polar perovskite K1/2Bi1/2TiO3

“…Generally, the frequency dispersion of d 33 with increasing temperature is related to the higher mobility of defects, such as space charge and/or structural defects. 67,68 The lack of frequency dispersion for all three cases of KBT indicates that thermal treatment did not induce any significant defects that are mobile within the measurement range of 400 °C. Although the quenching-induced increase in T d has been reported for different piezoelectric compositions, their underlying mechanisms are not well understood.…”

Hardening Effect on the Electromechanical Properties of KNN-Based Ceramics Using a Composite Approach

“…In Figure c, the T R–T and T C values initially keep it constant and then shift toward higher temperatures as the KCN content increases. T R–T relates to the thermal energy required to remove symmetry strain in the crystal structure. , Local electric and stress fields increase the microstrain of the composites, resulting in a T R–T shift to a higher temperature. The increase in T C may be due to the stabilization of the ferroelectric phase by the pegging effect of the local electric and stress fields on the ferroelectric domains .…”

Dielectric, Ferroelectric, and High-Temperature Strain Behavior of Rare Earth Ce-Doped 0.67BiFeO3–0.33BaTiO3 Lead-Free Ferroelectric Ceramics

“…In the past few decades, lead-free piezoelectric ceramics have become an active research area. Significant advancements have been achieved using (Bi 0.5 Na 0.5 )­TiO 3 (BNT), BiFeO 3 (BF), and K 0.5 Na 0.5 NbO 3 as the base materials for lead-free ceramics. − Compared to other lead-free ceramics, the BF system demonstrates a higher Curie temperature ( T c ) and depolarization temperature, making it more suitable for practical applications at high temperatures …”