Mechanical activation of synthesis of laminated compounds in Bi2O3-TiO2-Nb2O5 system

Using the method of high-temperature X-ray diffraction analysis synthesis of laminated compounds 2Bi2O3·3TiO2, 5Bi2O3·3Nb2O5 and 3Bi2O3·2TiO2·Nb2O5 is studied with the aid of mechanical activation. On the basis of the obtained results the conclusion is made that at the machanical activation stage the oxides at the atomic level, and as a result a solid solution is formed on the basis of bismuth oxide, which structure is close to the structure of high-temperature form δ-Bi2O3, and there occurs redistribution of cations characteristic for the future compound. When the mixture is heated up again, the product crystallizes, in which layers with the perovskite structure alternate with those of high-temperature form δ-Bi2O3