Size tunable synthesis of highly crystalline BaTiO3 nanoparticles using salt-assisted spray pyrolysis

Highly crystalline, dense BaTiO3 nanoparticles in a size range from 30 to 360 nm with a narrow size distribution (sigma(g) = 1.2-1.4) were prepared at various synthesis temperatures using a salt-assisted spray pyrolysis (SASP) method without the need for post-annealing. The effect of synthesis temperature on particle size, crystallinity and surface morphology of the nanoparticles were characterized by X-ray diffraction and scanning/transmission electron microscopy. The nature of the crystalline structure was analyzed by Rietveld refinement and Raman spectroscopy. The particle size decreased with decreasing operation temperature. The crystal phase was transformed from tetragonal to cubic at a particles size of about 50 nm at room temperature. SASP can be used to produce high weight fraction of tetragonal BaTiO3 nanoparticles down to 64 nm in a single step.