Surface Decomposition of Strontium‐Doped Soft PbZrO ₃ –PbTiO ₃

Abstract

Sintering temperature has a pronounced effect on perovskite phase stability at the surface of Pb 0.88 Sr 0.12 Zr 0.54 Ti 0.44 Sb 0.02 O 3 (PSZT) soft piezoelectric ceramics ( d 33 ≈ 600 pC/N). After sintering 4 h at 1070°C, XRD reveals only perovskite PSZT peaks in the bulk and at the surface. As sintering temperature increases, XRD from the ceramic surface reveals a second‐phase peak at ∼27° (2θ), 0.316 nm ( d ‐spacing). After 4 h at 1280°C, further second‐phase peaks are observed, confirming it to be monoclinic ZrO 2 , accompanied by a strong increase in the degree of tetragonality of the perovskite phase. These observations are consistent with decomposition of the PSZT to ZrO 2 and tetragonal PZT (PbZrO 3 –PbTiO 3 ) associated with PbO loss. SEM and cross‐sectional TEM indicated that surface decomposition had progressed ∼0.5 mm into the sample after 4 h at 1280°C.