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PFM characterization of (K<inf>0.5</inf>Na<inf>0.5</inf>) <inf>0.95</inf>La<inf>0.05</inf>(Nb<inf>0.9</inf>Ti<inf>0.05</inf>)O <inf>2.9</inf> ceramics lead free

Abstract:

The results of ferroelectric properties studies of KNN doped with La and Ti and sintered at temperatures in the interval of 1100 °C-1190 °C are presented in this work. The doping was achieved by the substitution of La for ions in A sites and Ti for ions in the B sites. Values of 94 % of the theoretical density were accomplished. The effect of the sintering temperature and the inclusion of the La and Ti cations in the KNN structure is evident through the shift in the ferroelectric-paraelectric transition temperature of ∼110 °C with respect to that of pure KNN (420 °C). Microstructure and ferroelectric analyses were carried out using Piezoresponse Force Microscopy (PFM) and hysteresis loops with interesting results, δPr = 9 (μC/cm2) and Pr/Pmax = 0.41, even when the saturation of the materials is not reached. © 2013 Springer-Verlag Berlin Heidelberg.