Degree of phase transformations in the conditions of polythermal synthesis of SrBaFeMoO6–δ

The sequence of phase transformations during the crystallization of SrBaFeMoO6 –δ by the solid-phase technique from a stoichiometric mixture of simple oxides SrCO3 þ BaCO3 þ 0.5Fe2O3 þ MoO3 was studied. It has been established that the synthesis of barium – strontium ferromolybdate proceeds through a series of sequential - parallel stages. It was found that to minimize the effect of intermediate reaction products, it is necessary to use combined synthesis modes. As a result of using combined synthesis modes for annealing for 20 h and T ¼ 1443 K in vacuum of 10 5 Torr at the pressure of residual oxygen gas 10 8 Pa, it was possible to obtain a single-phase barium – strontium ferromolybdate compound with superstructural ordering of iron and molybdenum cations