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

Lead-free (Na0.5K0.5)NbO3 ceramics doped with CaTiO3 (0–3 mol%) have been prepared by the conventional mixed oxide method in this paper. All of the CaTiO3 doped (Na0.5K0.5)NbO3 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 CaTiO3 is very effective in preventing the deliquescence and in improving the electric properties of (Na0.5K0.5)NbO3 ceramics. Finally, surface acoustic wave devices based on lead-free ceramics have been successfully fabricated and their characterization is presented.