The Fabrication and Characteristics of Sr{sub}(1-x)Ba{sub}xBi{sub}4Ti{sub}4O{sub}15 Functionally Graded Thin Films by Sol-Gel Method

摘要

Thin films of Sr{sub}(1-x)Ba{sub}xBi{sub}4Ti{sub}4O{sub}15 (SBBT, x=0, 0.2, 0.4, 0.5, 0.6, 0.8, 1.0) with gradients in composition were prepared on silicon(100) substrate by a modified sol-gel technique using the salts of Sr, Ba, Bi and TiO{sub}2 as sources. Two types of graded thin films were designed. A special heating treatment procedure was employed in this study to form the uniform composition gradients at the temperature below 850°C. The results of Auger depth profiling indicate that the special process produces smooth and linear composition gradients. X-ray diffraction study clearly shows the formation of the Bi-based layered structure. Some of the peaks of the SrBi{sub}4Ti{sub}4O{sub}15, BaBi{sub}4Ti{sub}4O{sub}15 and the graded SBBT thin films were analyzed, as well as the relationship between the microstructural evolution of graded thin films and annealing conditions.