Influence of the synthesis method on the preparation of barium titanate nanoparticles

Dielectric barium titanate nanoparticles are essential to develop reliable microelectronic devices. However, their dielectric properties largely depend on the synthesis method used. Hence, we developed BaTiO3 nanoparticles by various synthesis methods seeking to compare and evaluate their crystal structure, size, and homogeneity. Syntheses were carried out by four distinct synthesis methods: polymeric precursor (Pechini), electrochemical, hydrothermal and microwave-assisted hydrothermal. X-ray diffraction and Raman spectroscopy analysis revealed the formation of barium titanate in cubic and tetragonal structures. The nanoparticles synthesized have BET superficial areas varying in the range 10-15 m2 g−1. Pechini method propitiated the formation of smaller particles than the other methods, i.e. 44.0 ± 15 nm. By the electrochemical synthesis method the particles were obtained with 67.0 ± 20 nm of diameter, with large distribution in particle size. The use of hydrothermal methods conducted to various particle size distributions; while particles of 180.0 ± 60 nm were formed using conventional hydrothermal synthesis, smaller particles (66.0 ± 16 nm) were formed using the microwave-assisted hydrothermal synthesis in lower reaction times (six fold). All four methods were effective to synthesize crystalline BaTiO3 nanoparticles, with different sizes and structural characteristics. Thus, the choice of the suitable synthesis method will depend on the desired properties of the BaTiO3 nanoparticles.