Controlled homogeneity of the precursor gel in the synthesis of SrTiO3 nanoparticles by an epoxide assisted sol–gel route

Perovskite-type SrTiO3 nanoparticles of 50–100 nm were synthesized by a sol–gel method using propylene oxide as a gelation agent. The observation of the process of gel formation and the characterization of the obtained particles show that the addition of a certain amount of ethanol to the aqueous solution, where the gelation reaction takes place, plays a decisive role in the homogeneity of the precursor gel: ethanol decreases the huge difference of chemical reactivity between the individual precursor ions in the solution, increasing the homogeneity of the gels, as the amount of ethanol added is increased. The high homogeneity of the precursor gels allowed the formation of SrTiO3 nanoparticles by a short calcination of the precursor gel at 700 °C for 10 min.