Preparation of tetragonal barium titanate nanopowders by microwave solid-state synthesis

Tetragonal-phase BaTiO₃ powders of particle size 370 nm were synthesized by microwave sintering at 850 °C. The raw materials were BaCO₃, TiO₂, and alanine. SiC microspheres were used as microwave conductors. The effects of the holding time, sintering aids, and SiC addition on the preparation of BaTiO₃ were investigated. The results indicate that the addition of SiC as a microwave acceptor leads to formation of microwave micro-regions. This enables uniform heating of the raw materials and decreases the calcination temperature needed to obtain BaTiO₃. Alanine coordinates with Ba, and this loosens the metal–CO₃ bond and promotes separation of CO₂, decreases the BaCO₃ decomposition temperature, and provides a higher nucleation site density. It gives an idea about the microwave solid-state synthesis of BaTiO₃ powder.