Microstructural evolution and macroscopic property relationship in antiferroelectric lead lanthanum stannate zirconate titanate ceramics

The antiferroelectric (AFE) Pb0.97La0.02(Zr0.60Sn0.30Ti0.10)O-3 ceramic has a composition near the morphotropic phase boundary that separates the AFE from the ferroelectric (FE) phase. Its structural changes as well as macroscopic properties were investigated over a temperature range of -180-300 degreesC using transmission electron microscopy, dielectric spectroscopy, and Sawyer-Tower polarization measurements. The previously reported tetragonal AFE phase is shown to be an incommensurate orthorhombic phase and it exhibits a sequence of phase transformations on heating from the incommensurate AFE to a multicell cubic, then to a simple cubic phase. This microstructural evolution with temperature is consistent with the corresponding macroscopic dielectric and AFE behaviors. The temperature dependence of the AFE-FE switching field is closely associated with the corresponding temperature dependence of the incommensurate modulation wavelength. (C) 2003 American Institute of Physics.