Modification Mechanism and Dielectric Property Regulation of SnO2-Doped Ba0.6Sr0.4TiO3 Ceramics
Barium strontium titanate(BarSr1-rTiO3,BST)ferroelectric material is considered an important ma-terial in dynamic random access memory,microwave tuner,phase shifter,and other applications because of its good dielectric,ferroelectric,and pyroelectric properties.In this study,the(1-r)Ba0.6Sr0.4TiO3-rSnO2(BST-Sn)ce-ramics were prepared via the solid-phase sintering method.The effects of different contents of SnO2 on the micro-structure and dielectric properties of the BST system were examined via X-ray diffraction,scanning electron micros-copy,and the LCR digital bridge test system.The theoretical calculation results show that the ratio of lattice con-stant c to lattice constant a of BST decreases and the band gap increases with an increase in the incorporation ratio of SnO2.When the doping ratio of SnO2 is 0.05,the band gap reaches a maximum of 1.889 eV.The results of band and state density show that an increase in band gap is caused by the movement of Ti atoms'3d orbitals towards high energy.Secondly,the dielectric constant of pure BST ceramics,prepared experimentally,is 3 227,and the intro-duction of SnO2 reduces the dielectric constant of BST ceramics.
first principlesSnO2 doped BSTBST ceramicelectronic structuresolid state sintering method
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