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Barium strontium titanate (Ba 1-x Sr x TiO 3 , referred BST) material is a ferroelectric material with excellent performance , BST Curie temperature of the material through the Ba / Sr ratio is adjusted , the appropriate components of the BST material near the Curie temperature can be obtained at room temperature excellent dielectric properties, is the ideal dielectric material . In this paper, the sol - gel method, study of BST thin films prepared by optimizing the process parameters, prepared BST films with good performance . Acetic acid , barium acetate , strontium titanate as reactants , acetic acid and ethanol as solvent , acetylacetone as chelating agent to control the reaction temperature is 50 ℃ 7 0 ℃, the amount of water does not exceed 5% of the prepared sol stability. Film by spin coating method , select the appropriate conditions for preparing the coating uniformity good wet film , heat treatment process for wet film studies , the use of XRD, SEM analysis by means of film to study the dielectric properties of the films , combined XRD, SEM analysis to determine the annealing temperature at 650 ℃ 7 00 ℃, holding time of 30min under these conditions the surface of BST thin films prepared dense , smooth, crystalline good performance. The test frequency at 1kHz , 550 ℃ annealed relative dielectric constant of the BST film series only 48 6 2, with the annealing temperature , the different Ba / Sr dielectric films were there are different degrees, while for 30min at 700 ℃ , BST64 film shows good dielectric properties , relative permittivity εr reached 384 , the dielectric loss tanδ of only about 0.02 . Treated at different annealing temperature change in dielectric constant of the BST film stability, low dielectric loss and changes smoothly ; With the test frequency increases , BST dielectric constant slight decline , the dielectric loss is increasing rapidly. Produce this was mainly due to the dielectric anomaly at high frequencies there is a certain barrier electrode resistance and interfaces , as well as part of the BST films exist leaks caused by grain boundaries . At 20 ℃ 1 00 ℃, 1kHz test frequency, a film composed of BST64 relative dielectric constant εr at 237 3 84 between the dielectric loss tanδ 0.018 0 .073 between showing good dielectric properties.
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