B-site substitutions and phase transitions in solid solutions on the base of (Na0.5Bi0.5)TiO3

Substitutions of the zirconium and tin ions along with the indium-niobium and iron-niobium complexes for titanium in the barium modified NBT solid solutions impact the formation of phases in the process of the solid state synthesis and the relative stability of the antiferroelectric and ferroelectric phases. We showed that the synthesis of solid solutions is a multi-step process during which a number of intermediate phases (depending on the solid solution composition and the annealing temperature) are formed. The sintering temperature to 1000 - 1100 C allows to obtain single phase solid solutions. The increase of the substituting ion content results in a linear variation in the lattice unit cell size. At the same time it leads to a change in the relative stability of the antiferroelectric and ferroelectric phases according to the variation of the tolerance factor. Substitutions by ions with a radius larger than the radius of the initial ion leads to a decrease of the ferroelectric-antiferroelectric phase transition temperature while the smaller ion substitutions produce the opposite effect.