Synthesis and Characterization of 0.9PMN-0.1PT Powders by the Use of a Modified Columbite Precursor

Abstract

The complex perovskite compound 0.9PbMg1/3Nb2/3O3-0.1PbTiO3 is one of the most promising relaxor ceramic because the addition of lead titanate increases Tm by about 5°C/mol% from intrinsic Tm value for pure PMN (near –7 to -15°C). A Ti-modified columbite precursor was used to prepare PMN-PT powders containing single perovskite phase. This variation on columbite route includes Ti insertion in MgNb2O6 orthorhombic structure so that individual PT synthesis becomes unnecessary. Furthermore, effects of Li additive on columbite and PMN-PT structures were studied by XRD to verify the phase formation at each processing step. XRD data were also used for the structural refinement by Rietveld method. The additive acts increasing columbite powders crystallinity, and the amount of perovskite phase was insignificantly decreased by lithium addition. By SEM micrographs it was observed that Li presence in PMN-PT powders leads to the formation of rounded primary particles and for 1mol% of additive, the grain size is not changed, different from when this concentration is enhanced to 2mol%.