Progress on the doping and phase boundary design of potassium–sodium niobate lead-free ceramics

Abstract

Potassium–sodium niobate (K,Na)NbO3/(KNN) lead-free ceramics have drawn vast amount of attention as one of the effective alternatives to lead-based ones. In recent years, the author’s group concentrated their work on KNN-based ceramics. This paper reviews the main obtained results in authors’ laboratory on how to enhance the piezoelectric properties of KNN-based ceramics, including the ions or compounds substitution, the constructing and types of phase boundaries near room temperature, the investigation of other tools (sintering aids, synthesis technique, poling conditions) on properties. All the published papers up to now show the developing higher performance with maintaining high Curie temperature of KNN-based ceramics which has great potential for the future and is the key to success for the field.