Solid state synthesis and sintering of solid solutions of BNT–xBKT

Various compositions of the solid solution system (100 − x) Bi0,5Na0,5TiO3–xBi0,5K0,5TiO3 (x = 0, 10, 25, 50, 75, 90, 100) were prepared by the mixed oxide route. The formation reaction was analyzed by thermogravimetry coupled with mass spectroscopy and differential scanning calorimetry. In situ high temperature X-ray diffraction up to 770 °C indicated emerging and vanishing of phases during the calcination. Intermediate phases such as alkalipolytitanate (Na/K)2Ti6O13 and bismuth titanate Bi2Ti2O7 were identified as forming the perovskite phase. The formation reactions were proposed based on the data obtained. Furthermore the microstructure and the dielectric behavior of the sintered samples were observed by scanning electron microscopy, impedance spectrometry and polarization measurements.