Narrow sintering temperature window for (K, Na)NbO₃‐based lead‐free piezoceramics caused by compositional segregation

Abstract

Abstract In this paper, a typical Li‐ and Ta/Sb‐modified alkaline niobate‐based ceramics prepared by conventional sintering were investigated in terms of different sintering temperatures and dwelling times. Compositional segregation phenomenon is found to exist in the alkaline niobate‐based ceramics sintered at the temperatures above their melting points. As a result, microstructures of the ceramics become nonuniform, and electrical properties of them are degraded. Results indicate that compositional segregation is also a factor in the narrow sintering temperature window for alkaline niobate‐based ceramics.