The Route for Synthesis of Agglomeration-Free Barium Strontium Titanate Nanoparticles Using Ultrasonic Spray Nozzle System

摘要

Barium strontium titanate nanoparticles of spherical morphology and variable sizes could be synthesized by alkoxide-hydrox-ide sol-precipitation method, adopting an ultrasonic spray nozzle system. In the warm aqueous solution of barium and/or strontium hydroxide, a diluted solution of titanium isopropoxide (TIIP) in isopropanol was introduced as fine droplets produced by passing the solution through the ultrasonic nozzle. Phase-pure nanocrystals were produced. They were spherical, agglomeration-free, and fairly narrow in particle-size distribution. The average particle size can be controlled by changing the precursor concentration. When the TIIP concentration was increased above a certain critical value, a further increase in the particle size was interrupted as many doublets and triplets of particles were formed. The selection of spraying the precursor solution was critical for obtaining monodispersity, and it is found that confining the TIIP is crucial to obtain agglomeration-free nanoparticles.