High‐performance KNN piezoceramics with reproducibility and chemical stability. Part I: Solid‐state reaction route

Abstract

Abstract(K,Na)NbO3‐based compounds are attracting much attention for their high potential as Pb‐free piezoelectric ceramics. They have, however, three major drawbacks to overcome in order to achieve a mature development: densification, reproducibility, and chemical stability. In this first part, based on standard solid‐state reaction, the way to synthesize high‐density homogeneous ceramics with high piezoelectric performance and chemical stability is elucidated. It relies on a low‐temperature spark‐plasma sintering process, after the raw materials have been finely pulverized prior to reaction. The reproducibility, however, remains a pending issue due to the unavoidable random formation of parasitic phases.