The homogenized powder mixtures of BCZT and the binary reference systems were measured using a simultaneous thermo-gravimetric analyzer (TG-DTA) coupled to a mass spectrometer (STA-MS; STA449C Jupiter with QMS 403C Aeolos, Netzsch Gerätebau GmbH). The samples were heated up to 1000 °C at a rate of 5 °C/min in flowing synthetic air. All measurements were corrected for buoyancy.