Formation of Perovskite and Pyrochlore Phases during Mechanochemical Synthesis of Lead Ferroniobate

We have studied the effect of mechanical activation in lead ferroniobate synthesis on the formation of perovskite and pyrochlore phases during both mechanochemical synthesis and subsequent firing. It has been shown that, during mechanical activation, the first to form is the perovskite structure. During subsequent sintering of the material, the pyrochlore structure begins to form as well. As the firing temperature is raised to 650–750°C, the perovskite structure is again formed. We provide explanation for this process.