Mechanism of Phase Formation in Pb(Zr x Ti 1–x )O ₃ Synthesized by a Partial Oxalate Method

The phase formation mechanism, as well as the morpho‐tropic phase boundary, of lead zirconate titanate (PZT) processed by a partial oxalate method was investigated by simultaneous thermal analysis (TG‐DTA) and by qualitative and quantitative X‐ray diffraction (XRD). The results show that the Zr x Ti 1–x O 2 (ZT) phase reacts with PbO forming the PZT phase without intermediate phases. XRD analysis showed the coexistence of rhombohedral and tetragonal phases for 0.47 ≤ x ≤ 0.55 with the phase boundary composition for x = 0.51. For low calcination temperatures, preferential formation of the PZT rhombohedral phase was observed. A model for phase formation of PZT by the partial oxalate method is proposed based on the existence of two interfaces of reaction (PbO‐PZT and PZT‐ZT) and diffusion of cations.