Sinterability and Piezoelectric Properties of KNbO₃Ceramics after Substituting Pb and Na for K

Grain Size and Piezoelectric Properties of (Ba, K, Na)NbO3 Lead-Free Ceramics

“…13 On the other hand, we investigated the piezoelectric potential of K, NaNbO 3 ceramics by substituting a small amount of Pb for K and Na. 23,24 High piezoelectric properties were consequently obtained in a composition such as Pb 0.03 K 0.47 Na 0.47 NbO 3 with the assumption of A-site vacancies. In this study, it was experimentally investigated whether high piezoelectric properties are maintained even if Ba is used as a substituting element instead of Pb.…”

Influence of Sintering Temperature on Densification, Structure and Microstructure of Li and Sb Co-Modified (K,Na)NbO<sub>3</sub>-Based Ceramics

“…Although pressure-assisted sintering processes are effective in consolidating KNN ceramics by lowering the sintering temperature and hence suppressing the volatilization of alkali components, it is obvious that normal or pressureless sintering of these materials is more suitable for mass production. Most recent studies have concentrated on the development of KNN-based lead-free ceramics with enhanced piezoelectric properties through doping or texture control [8][9][10].…”

Lead-Free KNN-Based Piezoelectric Materials

“…Poled ceramics of KN show a relative permittivity of about 430 (at 1 MHz), dielectric loss of 2%, planar coupling coefficient (k p ) of 0.3, and polarization of 22 mC cm À2 [1,4]. It has been suggested that leaching the calcined powder with a 2% K 2 CO 3 solution, doping with Na, or adding Bi 0.5 Na 0.5 TiO 3 enhances the relative density, coupling factor, and mechanical quality factor of KN ceramics [1,5,6]. Metastable field-induced ferroelectricity is observed at adequately high applied fields and low temperatures [1] An in-depth study by D. Baker et al showed that the classic KNN phase diagram needs a minor modification around the K 0.3 Na 0.7 NbO 3 composition since a phase coexistence region was identified for the monoclinic to tetragonal first order phase transition in a temperature range of 200-210 C [7].…”