Influence of cation substitution on the phase formation kinetics of Sr 0. 7Bi 2.3Ta 2O 9 thin films

• Published in: Journal of the European Ceramic Society Vol. 24; no. 6; pp. 1603 - 1606
• Main Authors: Kwak, Woo-Chul, Sung, Yun-Mo
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 2004
• Subjects: Kinetics; Perovskite; Sol-gel process; X-ray methods; Perovskite; Films; X-ray methods; Kinetics; Sol-gel process
• ISSN: 0955-2219; 1873-619X
• DOI: 10.1016/S0955-2219(03)00396-0

The Ta 5+ ions in sol-gel derived Sr 0.7Bi 23Ta 2O 9(SBT) thin films were partially substituted by Zr 4+ to form Sr 0.7Bi 2.3Ta 1.7Zr 0.30 9 (SBTZ) thin films and Aurivillius phase formation characteristics were compared for each thin film. X-ray diffraction (XRD) analyses were performed on the thin films heated in the range of 730–760 °C at 10 °C intervals and it was found that phase formation and crystal growth were greatly affected by the film composition and crystallization temperature. Johnson–Mehl–Avrami (JMA) isothermal kinetic analyses were performed on the XRD results and activation energy and Avrami exponent values were determined for the fluorite-to-Aurivillus phase transformation. A reduction of ∼82 kJ/mol in activation energy was observed for the SBTZ thin films, which revealing the key reason of enhanced kinetics in SBTZ. XRD and scanning electron microscopy (SEM) showed the remaining of fluorite phase in SBT and the formation of a secondary phase in SBTZ.