Formation of BaTiO_3 nanoparticles from an aqueous precursor by flame-assisted spray pyrolysis

摘要

By manipulating process parameters, BaTiO_3 nanoparticles with tunable size were successfully prepared by flame-assisted spray pyrolysis (FASP) from an aqueous solution of barium acetate and titanium-tetra-isopropoxite. Particle size was controlled over a wide range (from about 23 to 71 nm) by varying the concentration of precursor and methane flow rate. Flame temperature was a key factor in producing particles with a narrow size distribution. The BaTiO_3 nanoparticles were cubic in crystal structure, dense, spherical and softly agglomerated. The particles contained OH, carboxyl and CO_2 bonding groups that could be completely removed by post-heat treatment. At room temperature, BaTiO_3 pellets had relatively high dielectric constants (2578.8-3611.8) with loss factors ranging from 2.6 percent to 7.1 percent at the frequency of 1 kHz. The results of this study indicate that BaTiO_3 nanoparticles can be fabricated using continuous and industrially applicable FASP.