Exploration into Synthesis of Tetragonal Phase BaTiO3 Based on Isopropanol Solvothermal Process and Its Mechanism
With Ba(OH)2·8H2O and Ti(OC4H9)4 as raw materials,and isopropanol(IPA)as solvent,tetragonal-rich BaTiO3(BTO)nanopowder was synthesized by adopting solvothermal process.Effects of Ba/Ti ratio,pH value,solvothermal temperature and time on synthesis of tetragonal-rich BTO powders were investigated,and the mechanism of IPA in the solvothermal process for synthesis of BTO powders was also characterized by X-ray diffraction and scanning electron microscopy.It is found that in the solvothermal process,IPA will preferentially provide certain—OH to promote the hydrolysis of Ti(OC4H9)4,generating TiO6 octahedra to interconnect with Ba2+,which is gradually transformed into the tetragonal phase BaTiO3 with regular morphology after phase transition,dissolution of small particles,and recrystallization in a low alkalinity environment.Experimental results show that under the following conditions including Ba/Ti ratio of 1.6,pH of 10 for the system,a solvothermal process at 220℃for 24 h,calcination at 950℃for 2 h,the synthesized tetragonal-rich BTO nanopowder is well dispersed with regular morphology,square or nearly square shape,with c/a value of 1.0094 and particle size of 124 nm on average.
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