Synthesis of Nanocrystalline Materials Based on the Bi2O3-TiO2 System

Resumo

Nanocrystalline bismuth titanates Bi₂Ti₄O₁₁ (115±5 nm), Bi₄Ti₃O₁₂ (60±5 nm), Bi₂Ti₂O₇ (105±5 nm), Bi₈TiO₁₄ (82±5 nm), and Bi₁₂TiO₂₀ (102±5 nm) were synthesized by heat treatment of the coprecipitated composition. It was revealed that the crystallite sizes of the target materials are determined by the minimum crystallite size of the first phase to crystallize in the reaction system. The process parameters of the synthesis and of the sintering of the materials were found to depend on the melting point of the surface (nonautonomous) phase. It was shown that the formation of the materials is mainly influenced by the kinetic factor, and the influence of the structural features is less pronounced.