Compositional variation in 0.65 PbMg2/3Nb1/3O3-0.35 PbTiO3 single crystals grown by high temperature solution growth technique

Single crystals of lead magnesium niobate titanate, 0.65 PbMg2/3Nb1/3O3(PMN)-0.35PbTiO3(PT) were grown using flux method near morphotropic phase boundary (MPB) composition. The crystals grown at the centre of the platinum crucible were found to PT deficient compared to those grown near the walls of the crucibles. A variation of ∝3.8 mol% in PT concentration was found in the crystals grown at the wall and at the centre of the crucible. The difference in the chemical composition of crystals grown at the centre and the near the wall of the crucible was observed by X-ray diffraction, EDXRF, dielectric and thermal measurements. The presence of PT rich and deficient crystals is explained in terms of the segregation coefficient of PT in PMN. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)