Phase transition and temperature stability of KNN-based lead-free piezoceramics

Abstract

Three step sintering method has been introduced in KNN-based lead free piezoceramics. The phase structure of the ceramics transform from rhombohedral phase to the coexistence of rhombohedral phase and tetragonal phase, and phase transition temperature shifts to −10 °C by three step sintering. Excellent piezoelectric properties have been obtained, d₃₃ = 405pC/N at room temperature, the d₃₃ values are above the 300pC/N from room temperature to around 200 °C.

Keywords:

• KNN
• three step sintering
• polymorphic phase transition

Additional information

Funding

This work was support by University Natural Science Research Project of Anhui Province (KJ2018A0458) and Natural Science Foundation of Anhui Province under Grant Nos. 2008085ME133 and 1908085ME153).