Rare earth element boosting temperature stability of (K,Na)NbO3-based ceramics.

It is difficult to realize the balanced development of piezoelectric response {piezoelectric constant (d 33) and strain} and temperature stability of potassium-sodium niobate ceramics. Here, we constructed one kind of lead-free piezoceramic system of 0.965K 0.45 Na 0.55 Nb 0.96 Sb 0.04 O 3 -0.035(Bi 1- x Ho x) 0.5 Na 0.5 HfO 3 , and rhombohedral & tetragonal (R-T) multiphase coexistence maintains in a wide compositional range of x = 0.05–0.55. Greatly improved temperature stability of piezoelectric response is realized by doping rare earth Ho. Excellent temperature stability of both strain and d 33 mainly originates from the weak temperature dependence of domain structure as well as the increased R-T phase transition temperature. As a result, the addition of rare earth Ho can boost temperature stability of potassium-sodium niobate-based ceramics. Image 1 • Superior temperature stability of piezoresponse is achieved in KNN ceramics. • Weak temperature dependence of domain structure matches the stable piezoresponse. • Increased phase transition temperature contributes the good temperature stability. [ABSTRACT FROM AUTHOR]