Strontium bismuth tantalate thin films having composition of Sr0.7Bi2.4Ta2O9 (SBT) were deposited on the pre-crystallized SBT seed layer with the same composition using sol-gel and spin coating methods. Unseeded and seeded SBT thin films were crystallized to fluorite by heating at 600degreesC for 1 h and they were further heated in the range of 710-740degreesC. at 10degreesC intervals for different time periods to analyze fluorite-to-Aurivillius phase transformation characteristics. X-ray diffraction (XRD) results on the heated films indicate that the phase transformation kinetics is greatly enhanced in the seeded ones. Quantitative X-ray diffraction (Q-XRD) was performed and the results were used for Johnson-Mehl-Avrami (JMA) isothermal kinetic analyses. From JMA plots Avrami exponent values for unseeded and seeded films were determined as similar to1.5 and. similar to1.1, respectively, which implies that each film has a different nucleation mechanism. Using Arrhenius plots the activation energy values for the phase transformation of unseeded and seeded films were determined as similar to263 and similar to183 kJ/mol, respectively. The nucleation mechanism difference and the resultant activation energy difference provide the origin of enhanced kinetics in seeded SBT thin films. (C) 2003. Elsevier Science B.V. All rights reserved.