Figure depicts the XRD pattern of a sample calcined at 1200 °C for 4 h; conditions similar to those typically reported for undoped BCZT . The recorded diffractogram reveals the presence of the secondary phase CaTiO3 and a polytitanate phase. Although CaTiO3 is fully dissolved in the BCZT matrix at sintering temperatures, typical calcination temperatures of 1200-1300 °C are not sufficient to form a thermodynamically stable BCZT solid-solution (see Figure ). Furthermore, the solubility of Ca 2+ in BCZT diminishes upon cooling and a fraction of CaTiO3 precipitates .