Hydrothermal Synthesis of Tetragonal Barium Titanate from Barium Hydroxide and Titanium Dioxide under Moderate Conditions

Tetragonal BaTiO 3 powders were prepared hydrothermally, using Ba(OH) 2 ·8H 2 O and TiO 2 (anatase), in the absence of anions such as chloride ions, at a temperature of 220°C for several days. Characterization via X‐ray diffractometry, scanning electron microscopy, and differential scanning calorimetry confirmed that increasing the Ba:Ti molar ratios (from 1:1 to 4:1) and alkaline concentrations (from 1.0 M to 3.0 M ) promotes the formation of tetragonal BaTiO 3 .