The small amount of CaZrTi₂O₇ in the BCZT mixture disappears above 700 °C and the intensity of ZrO2 reflections decreases to below the detection limit at 750 °C. This suggests that Zr 4+ ions are mostly incorporated into the CaZrO3 perovskite at this point. The decomposition of CaCO3 into CaO (Eq. 1) is accelerated and excess CaO can be identified in the XRD patterns (diffraction peak at 2𝜃 =37° in Figure ). Subsequent reactions with ZrO2 and TiO2 (Eq. 2 and 3) are observed up to 750 °C. This process is in good agreement with thermal analysis and CO2 evolution, described in chapter 3.1., and with the work of Karunadasa et al. .