Investigation of temperature-induced phase transitions in (Ba,Ca)(Zr,Ti)O3 ceramics

Lead-free piezoelectric ceramics with perovskite structure can demonstrate excellent properties when their compositions are projected with sequences of specific phase transitions and/or coexistence of phases. The main problem, however, is that the use of isolate techniques to characterize the phase transitions of perovskite ceramics can be inconclusive or require intricate and expensive procedures. This study aimed to explore the use of the combination of different techniques to investigate the temperature-induced phase transitions and phase coexistence in ceramics of 0.66Ba(Zr0.2Ti0.8)O3–0.44(Ba0.7Ca0.3)TiO3 (0.44BCZT). The phase transitions of ceramics were characterized in temperature ranges from 0 to 160 °C using the techniques of dilatometry, differential scanning calorimetry, dielectric impedance, pyroelectric coefficient and X-ray diffraction. This study has shown the existence of three-phase transitions for the 0.44BCZT composition in the range of temperature and identified physical anomalies that confirm the phase coexistence.