Study of microstructure and dielectric properties of PMN-PZT ceramics via a mixed powder method including microemulsion derived PZT powder

Abstract

In this research, (X)PZT-(1-X)PMN ceramics (where X is 0.25, 0.5 and 0.75) were achieved from a conventional mixed-oxide method. Lead Zirconate titanate (PZT) powders with composition near the morphotropic phase boundary have been synthesized via a microemulsion processing route. Modified mixed oxides method was used for obtaining single phase Lead Magnesium niobate (PMN) powder with high relative density (98% of T.D.) and good electrical properties (dielectric constant of ≈10 4 at room temperature). Two-step sintering (TSS) has been applied to suppress the accelerated grain growth of PZT-PMN composite compacts in the last sintering stage. The produced samples with high PZT content showed low densities due to the low compaction ratio of PZT powder. The dielectric properties of PZT-rich and PMN-rich materials were high (dielectric constant of about 0.7×10 3 and 1×10 3 was measured for PZT-rich and PMN-rich ceramics, respectively) while the other sample exhibited lower dielectric properties. The X-ray diffraction analysis of the sintered samples indicated that PZT-PMN ceramic was produced successfully with traces of pyrochlore phase formed in the structure.