Structural characterization of 0.5PbMg 1/3Nb 2/3O 3–0.5Ba xPb (1− x) TiO 3 powders

Abstract

The present work reports the effects caused by barium on phase formation, morphology and sintering of lead magnesium niobate–lead titanate (PMN–50PT). Ab initio study of 0.5Pb(Mg 1/3Nb 2/3)O 3–0.5(Ba x Pb (1− x) TiO 3) ceramic powders, with x = 0, 0.20, and 0.40 was proposed, considering that the partial substitution of lead by barium can reestablish the equilibrium of monoclinic–tetragonal phases in the system. It was verified that even for 40 mol% of barium, it was possible to obtain pyrochlore-free PMN–PT powders. The increase of the lattice parameters of PMN–PT doped-powders confirmed dopant incorporation into the perovskite phase. The presence of barium improved the reactivity of the powders, with an average particle size of 120 nm for 40 mol% of barium against 167 nm for the pure sample. Although high barium content (40 mol%) was deleterious for a dense ceramic, contents up to 20 mol% allowed 95% density when sintered at 1100 °C for 4 h.