Synthesis, dielectric and microstructure studies of lead magnesium niobate stabilised using lead titanate

Abstract

Lead Titanate (PbTiO₃, referred as PT) is used as a phase stabiliser in Lead Magnesium Niobate [Pb(Mg_1/3Nb_2/3)O₃, designated as PMN] to stabilise perovskite phase. Two different approaches have been used for adding PbTiO₃. In the first, stoichiometric amounts of TiO₂ and PbO are added with the starting reagents of PMN to fabricate 0.9PMN – 0.1PT and in the second, 10 mol% PbTiO₃ has been directly added to the presintered PMN powder. Phase analysis reveals formation of single phase perovskite PMN in all the cases. Dielectric constant of 21200 (at −11°C, 1 KHz) for pure PMN, 28000 (at 31°C, 1 KHz) for PMN + 10PT and 35000 (at 19°C, 1 KHz) for PMN – 10PT have been achieved. The microstructure exhibits well defined cubic grains of 2-3 μm average grain size.