Properties and structures of nonstoichiometric (K, Na)NbO3 based lead free ceramics
The 0.968[(K0.48Na0.52)]Nb0.95+xSb0.05O3 0.032(Bi0.5Na0.5)ZrO3 [KNNxS BNZ] lead free ceramics with nonstoichiometric niobium ion were fabricated via conventional solid state sintering technique and their piezoelectric, dielectric and ferroelectric properties were investigated. When x= 0.010, enhanced piezoelectric properties (d33 421 pC/N and kp 0.47) were obtained due to the construction of rhombohendral tetragonal phase boundary near room temperature. The KNNxS BNZ ceramics possesses enhanced Curie temperature (Tc) with improved piezoelectric constant. A large d33 of 421 pC/N and a high Tc 256 degC can be simultaneously induced in the ceramics with x= 0.010. Especially, good thermal stability was observed in a broad temperature range. The results indicated that our work could benefit development of KNN based ceramics and widen their application range. This article is protected by copyright. All rights reserved.