Metal substitution and atom displacement effects in pzt and pszt

First principles electronic structure calculations in the framework of Local Density (LD) theory have been performed for the lead zirconate-lead titanate (PZT) solid solution near the experimentally interesting antiferroelectric-ferroelectric phase boundary. The Discrete Variational Xx Method (DV-X”.) with an embedded cluster scheme was used to investigate electronic structure, energy levels, charge distribution and chemical bonding in the paraelectric (PE) and antiferroelectric (AFE) regions of the PZT phase diagram. Isovalent metal substitution at the Zr site leads to measurable changes in the band gap and charge distribution. Mössbauer isomer shift parameters for tin substituted compound PSZT have been calculated.