Synthesis of Bi4Ti3O12 by high energy milling of Bi2O3–TiO2 (anatase) mixtures

• Published in: Journal of thermal analysis and calorimetry 2016-12, Vol.126 (3), p.1507-1511
• Main Authors: Berbenni, V., Milanese, C., Bruni, G., Girella, A., Marini, A.
• Format: Article
• Language: English
• Subjects: Analytical Chemistry; Anatase; Bismuth titanate; Bismuth trioxide; Chemistry; Chemistry and Materials Science; Inorganic Chemistry; Liquid phases; Measurement Science and Instrumentation; Mechanical alloying; Mixtures; Oxides; Peritectic reactions; Physical Chemistry; Polymer Sciences; Titanium dioxide
• ISSN: 1388-6150; 1588-2926
• DOI: 10.1007/s10973-016-5807-x

The mechanism of Bi 4 Ti 3 O 12 formation starting from the two constituent oxides has been studied. Starting from a physical mixture, a solid-state reaction occurs between the two oxides that leads at ≈700 °C to a mixture of the two ternary oxides Bi 12 TiO 20  + Bi 4 Ti 3 O 12 along with unreacted precursor oxides. At T  ≈ 830 °C Bi 12 TiO 20 reacts with TiO 2 forming Bi 4 Ti 3 O 12 and, finally, at T  ≈ 850 °C, the residual Bi 12 TiO 20 undergoes the peritectic reaction that produces Bi 4 Ti 3 O 12 plus a liquid phase. However, the formation of Bi 4 Ti 3 O 12 is not complete at temperatures as high as 900 °C. Starting from a mechanically activated mixture, the intermediate Bi 12 TiO 20 only forms as a minority phase at a lower temperature ( T  ≈ 550 °C), and then it rapidly reacts to give Bi 4 Ti 3 O 12 . No trace of the peritectic reaction is found in the case of the activated mixture. The complete formation of Bi 4 Ti 3 O 12 can be obtained by 3-h annealing of the activated mixture at T  ≥ 650 °C. The heat capacity of the product phase Bi 4 Ti 3 O 12 has also been measured in the temperature range 50–300 °C.