In situ obsevations of solid-solid reaction : decomposition of barium titanyl oxylate and formation of barium titanate

• Autorzy: Isshiki T. , Nishio K. , Shiojiri M. , Noguchi H. , Deguchi Y. , Yamamoto H.
• Konferencja: Polish-Japanese Joint Seminar on Materials Analysis (1-3.09.1997 ; Warsaw, Poland)
• Języki publikacji: EN

Abstrakty

EN

The thermal decomposition of BaTiO(C₂O₄)₂ 4H₂O and formation of BaTiO₃ were investigated by thermogravimetric analysis (TGA), differential thermal analysis combined with mass-spectroscopy (DTA-MS), high-temperature X-ray diffraction (XRD), and in situ scanning electron microscopy (SEM) and transmission electron microscopy (TEM). TGA and DTA-MS showed that the dehydration occurred in a temperature range of 25 ÷ 240°C, followed by the decomposition of BaTiO(C₂O₄)₂ 4H₂O to BaCO₃, TiO₂, CO and CO₂ in a range of 240 ÷ 470°C. A porous structure showing the escape of CO and CO₂ gases was observed in an SEM image of a specimen at 400°C. Only diffuse peaks appeared in XRD charts in 200 ÷ 500°C, indicating that the BaCO₃ and TiO₂ are amorphous and/or micro-crystalline. XRD also disclosed that hexagonal BaTiO3 crystallites were formed by the solid-state reaction of the BaCO₃ and TiO₂ in range of 500 ÷ 650°C and then transformed to cubic crystals above 650°C. The direct formation of cubic BaTiO₃ crystals also occurred as a retareded reaction of the BaCO₃ and TiO₂ above 730°C.

• Wydawca: Institute of Electron Technology
• Czasopismo: Electron Technology
• Rocznik: 1998
• Tom: Vol. 31, No. 2
• Strony: 202--207
• Opis fizyczny: Bibliogr. 9 poz.

Twórcy

autor

Isshiki T.

autor

Nishio K.

autor

Shiojiri M.

autor

Noguchi H.

autor

Deguchi Y.

autor

Yamamoto H.

• Kyoto Instytute of Technology, Matsugasaki, Kyoto 606-0962, Japan