Solvothermal synthesis, characterization and formation mechanism of single-crystalline SrTiO3 dense spheres with monoethanolamine as reaction medium solvent

Single-crystal strontium titanate (SrTiO3) dense spheres have been synthesized via a solvothermal reaction route with monoethanolamine as reaction medium solvent. The as-synthesized SrTiO3 products were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, and selected area electron diffraction, respectively. The results demonstrated that the single-crystal SrTiO3 dense spheres are self-assembled by primary nanocrystallites. Based on the experimental results, the possible formation mechanism of the SrTiO3 spheres has been proposed. Moreover, by changing the solvent with diethanolamine and triethanolamine instead of monoethanolamine, the average diameter of the SrTiO3 dense spheres can be tuned from 100-150 nm to 50-70 nm.