Synthesis and structural characterization of the new solid solution Ba2−xSrxTiO4 (0 ≤ x ≤ 1): Effect of the method of synthesis on the polymorphic phase isolated

Investigation of the system Ba2TiO4–Sr2TiO4 resulted in the synthesis by classical ceramic route of the solid solution Ba2−xSrxTiO4 (0 < x ≤ 1) with orthorhombic Ba2TiO4-type structure. In the limit case Ba2TiO4 (x = 0), a mixture of monoclinic and orthorhombic polymorphs was obtained by this synthesis method. A route based on mechanochemical activation was also used to obtain these oxides. Milling of a 2BaO2/TiO2 powder mixture in a planetary mill produced the mechanosynthesis of nanosized crystalline Ba2TiO4. Moreover, mechanochemical activation followed by annealing at moderate temperature results in the stabilization at room temperature of the orthorhombic high-temperature Ba2TiO4 polymorph. By this approach Ba2−xSrxTiO4 (0 ≤ x ≤ 1) solid solution can be obtained at lower temperature and shorter synthesis times than usual.