The difference in the decomposition temperatures of BaCO3 and CaCO3 is also evident upon comparing the binary perovskite mixtures (Figure ) for the formation of BaTiO3, BaZrO3, CaTiO3, and CaZrO3, respectively, since all Ca-containing sample curves are shifted to lower temperatures, as predicted by the corresponding Ellingham diagram . Notably, the CaCO3 decomposition temperature for the CaZrO3 formation reaction (786 °C) fits better to the profile of the BCZT TG curve than that of CaTiO3 (809 °C; see Figure for DTA curves) .