Temperature-Dependent Phase Transitions in the Lead-Free Piezoceramics (1 – x – y)(Bi<sub>1/2</sub>Na<sub>1/2</sub>)TiO<sub>3</sub>–xBaTiO<sub>3</sub>–y(K<sub>0.5</sub>Na<sub>0.5</sub>)NbO<sub>3</sub> Observed by in situ Transmission Electron Microscopy and Dielectric Measurements
Lead-free piezoelectric (1 – x – y)(Bi1/2Na1/2)TiO3–xBaTiO3–y(K0.5Na0.5)NbO3 (BNT–BT–KNN) ceramics were examined in situ under increasing temperature in the transmission electron microscope. Changing superstructure reflections indicate a transition from rhombohedral to tetragonal to cubic phase with broad coexistence regions. The additional evolution of the microstructure in combination with dielectric measurements leads to a model of two relaxor-type phase evolutions with temperature.
American Ceramic Society. Journal, 2013, Vol 96, Issue 10, p. 3312-3324
In situ processing; Measurements; Niobium oxide; Piezoelectric ceramics; Transmission electron microscopy; Sodium