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Updated: May 23, 2026
Chemical Synthesis of Porous Barium Titanate Thin Film and Thermal Stabilization of Ferroelectric Phase by Porosity-Induced Strain
Published on: March 27, 2018
Influence of precursor synthesis temperature and hydrothermal alkaline medium on agglomeration and crystal phase of
1Department of Chemistry, Faculty of Engineering and Natural Sciences, Bursa Technical University, Bursa, Turkiye.
Abstract:
Phase-pure, cube-like barium titanate (BaTiO3) nanoparticles were synthesized via hydrothermal treatment of a single-source barium-titanium peroxo-hydroxide precursor. Precursor solutions prepared at room temperature, 0 °C, and -10 °C with various storage times exhibited Ba/Ti molar ratios ranging from 0.66 to 1.05 as determined by X-ray fluorescence. Cooling the precursor solution to -10 °C effectively suppressed the polymerization of Ti-O-Ti, yielding near-ideal stoichiometry and finer precursor particles. Subsequent hydrothermal processing in NH4OH, KOH, and NaOH (0.5-10 M, 100-200 °C) revealed the strong dependence of agglomeration and morphology on the alkaline medium. While NH4OH and KOH resulted in severe agglomeration and the formation of micrometer-scale conglomerates, hydrothermal treatment in 10 M NaOH at 200 °C produced well-faceted, weakly agglomerated cubic BaTiO3 particles with edge lengths of approximately 200-500 nm. The particle-size distribution was further tuned by reducing the solution volume from 60 to 10 mL and increasing the total Ba + Ti concentration from 0.05 to 0.30 M, leading to sharper cubic morphologies and bimodal size distributions at higher concentrations. X-ray diffraction combined with Rietveld refinement confirmed phase-pure BaTiO3 and demonstrated that the cooling rate governed the cubic-to-tetragonal phase transition through size- and strain-mediated stabilization. Fourier-transform infrared spectroscopy, Fourier-transform Raman spectroscopy, and thermogravimetric-differential thermal analysis verified characteristic titanate bonding and BaCO3 contamination (~20 wt.%) at high feedstock concentration. The combination of low-temperature precursor synthesis and NaOH-mediated hydrothermal processing provides a scalable strategy for preparing morphology-controlled BaTiO3 nanoparticles with potential relevance for electronic, electrooptic, and bioimaging applications.
