Accelerated processing route for KNN based piezoceramics

Abstract

It is known that the properties of potassium–sodium–niobate (KNN, K_0·46Na_0·54NbO₃) are sensitive to processing and that the most successful way of stabilising and improving material performance is proper doping of KNN. However, this leads to more complex material systems, whose synthesis is very time consuming to assess by conventional processing techniques. On the other hand, known high throughput routes impose a serious interference with conventional processing, resulting in significant differences of the findings, or inaccessibility of certain parameters. In this paper, an accelerated processing route is introduced and compared with conventional mixed oxide processing regarding the density, large signal piezoelectric charge constant, permittivity, loss tangent planar coupling factor, specific resistivity and microstructure. By means of three differently doped KNN based compositions, it is shown that the accelerated processing route yields reproducible results, which are equal or even superior to conventional techniques, while the processing time and the batch costs are significantly reduced.

Keywords:

• Lead free
• Piezoceramics
• High throughput processing
• HTE
• High throughput experimentation
• Accelerated processing
• KNN

Financial support from Bundesministerium für Bildung und Forschung/Federal Ministry for Education and Research (BMBF) under grant 03X4007A-H is gratefully acknowledged.