Hydrothermal synthesis of BaTiO3 from different Ti-precursors and microstructural and electrical properties of sintered samples with submicrometric grain size

Barium titanate submicrometric particles were synthesized at 180 °C in a closed PTFE-lined stainless steel reactor with continuous stirring. Precursors used for titanium were Degussa P25 TiO₂ or titanium isopropoxide (TIP). Barium hydroxide (Ba(OH)₂) was added in a Ba/Ti = 1.1 molar ratio and KOH was used as mineralizer. The obtained powders were characterized by XRD and Raman spectroscopy. Powders were uniaxially pressed into discs and sintered at 1250 °C. The resulting microstructures were characterized by XRD, SEM, and Raman spectroscopy. Electrical measurements were carried out in order to characterize the ferroelectric behavior. The Ti precursor determined the sample density and grain size distribution and, consequently, the electrical response.