Microstructure evolution of highly ordered Bi₄Si₃ O₁₂ microcrystals

This study reports the preparation of dendritic bismuth silicon oxide ( Bi_4Si_3 {O₁₂} ) microcrystals by using solid state reaction stages and heating of Bi_2O_3 SoO_2 powder mixture at 800°C for different holding times and ambient conditions. X-ray diffractometer (XRD) and scanning electron microscopy (SEM) were used to analyse the prepared microcrystals. XRD analysis revealed that microcrystals showed the eulytite structure, with a gradual decrease in the proportion of {Bi₁₂}{SiO₂₀} phase and a considerable increase in Bi_4Si_3 {O₁₂} phase as the holding time increased during heating at 800°C. This phenomenon is attributed to the occurrence of a transformation in the system, change of crystal composition and generation of dendritic-structuredmicrocrystals by increasing the holding time. An ordered structure similar to typical preferential orientation growth was formed with the growing epitaxial structure of Bi_4Si_3 {O₁₂} grains on the favourable microcrystal surface. However, the domain structure gradually disappeared after a certain period.