An investigation of (Na0.5K0.5)NbO3–CaTiO3 based lead-free ceramics and surface acoustic wave devices

Abstract Lead-free (Na 0.5 K 0.5 )NbO 3 ceramics doped with CaTiO 3 (0–3 mol%) have been prepared by the conventional mixed oxide method in this paper. All of the CaTiO 3 doped (Na 0.5 K 0.5 )NbO 3 specimens do not deliquesce as exposed to water for a long time. The samples are characterized by X-ray diffraction analysis, Raman scattering spectra, scanning electron microscopy, and atomic force microscopy. The dielectric, piezoelectric and ferroelectric properties are also investigated. The results show that the addition of CaTiO 3 is very effective in preventing the deliquescence and in improving the electric properties of (Na 0.5 K 0.5 )NbO 3 ceramics. Finally, surface acoustic wave devices based on lead-free ceramics have been successfully fabricated and their characterization is presented.