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Abstract: Ba0.7−x Sr0.3Mn x TiO3 (x =0, 0.025, 0.05) thin films have been prepared on copper foils using sol–gel method. The films were processed in an atmosphere with low oxygen pressure so that the substrate oxidation is avoided and the formation of the perovskite phase is allowed. XRD and SEM results showed that Mn doping enhanced the crystallization of the perovskite phase in the films. The Mn substitution prevents the reduction of Ti4+ to Ti3+, which is supported by XPS analysis. The Ba0.7−x Sr0.3Mn x TiO3 film with x =0.025 (BSMT25) exhibits preferred dielectric behavior and a lower leakage current density among the three thin films. The dielectric constant and loss of the BSMT25 film are 1213.5 and 0.065 at 1MHz and around zero field, which are mostly desired for embedded capacitor applications. The mechanism of Mn doping on improving the electrical properties of barium strontium titanate (BST) thin films was investigated. [Copyright &y& Elsevier]

Abstract: Ba0.5Sr0.5TiO3 (BST) thin films were deposited on copper foils via sol–gel method with La2O3 as a buffer layer. The films were processed in almost inert atmosphere so that the substrate oxidation was avoided while allowing the perovskite film phase to crystallize. The existence of a La2O3 buffer layer between the BST thin film and Cu foil improved the dielectric constant and reduced the leakage current density of the BST thin film. Meanwhile, the BST thin film exhibited ferroelectric character at room temperature, which was contrast to the para-electric behavior of the film without the buffer layer. Effects of La2O3 buffer layer on the crystallizability and microstructure of BST thin films were also investigated. [Copyright &y& Elsevier]