Solid-state reactions in powder mixtures are typically governed by kinetics and diffusion through the reaction layer. The increased number of constituents in Ca-and Zr-modified BaTiO3 increases the number of different interparticle contacts in starting powders and thus the number of possible secondary phases also increases compared to pure BaTiO3. For example, the ionic-size-related limited solubility of Ca 2+ in BaTiO3 has similarly been reported for the BCZT system . This results in the formation of a small amount of thermodynamically-stable CaTiO3 precipitates, which are present in most BCZT compositions . Even though these precipitates can be useful for ferroelectric hardening if properly engineered , they are not desirable for achieving high electromechanical strains . Another issue is the limited incorporation of BaZrO3 into the BCZT matrix, observable as a "shoulder" of all perovskite-assigned diffraction peaks in X-ray diffractograms . Furthermore, the titanium-rich Ba6Ti17O40 phase has been found to appear if the A/B ratio in the final sample is nonstoichiometric. This phase might produce leakage currents at the grain boundaries and is thus undesired .