Influence Of Dopant To Structure,property And Oxygen Diffusion Of BaTiO₃-based Ceramic

ABSTRACT: Multi-layer ceramic capacitor（MLCC） is an important electroniccomponent and is widely applied in industrial and agricultural, national defense, scientificresearch and daily life, and so on. Various countries have pay much attention to producecermic material used in the capacitor to adapt the MLCC’s development.BaTiO₃ferroelectric ceramic is the mainstream materials for MLCC. One of the impoetant meansto improve and enhance the BaTiO₃’s performance is to improve the existing materialssystem by introduce addition compositions, which could change the material’s composeand microstructure. The relationship between temperature, doping content and Dielectricproperties of BZTO, BZTO doped by CaO and MgO respectively were researched. Andthe microstructure analysis was done by SEM. The parameters of oxygen diffusion inBaTiO₃with different doping conditions was simulated by Moldy. The following was theconclusions:（1）The diffraction peaks of BZTO prepared by BaCO₃, ZrO₂, TiO₂move tosmall-angle. The curie temperature is lower. The Dielectric constant of BZTO with thesame ZrO₂content increase with prolonging of heat preservation time. The Loss Tangentis lower than0.25. The Loss tangent of BZTO with the same ZrO₂content increase withthe higher temperature. The prolonging of heat preservation time and the increase of ZrO₂content is good to the grain growth.（2）The doping of CaO make the curie temperature of BZTO get higher. TheDielectric constant of BCZTO decrease with the increase of the doping content of CaO.The Dielectric constant of BCZTO with the same CaO content increase with prolonging ofheat preservation time. The Loss Tangent is lower than0.15. The Loss tangent of BCZTOwith the same CaO content increase with the higher temperature. The prolonging of heatpreservation time and the increase of CaO content is good to the grain growth.（3） The doping of MgO make the curie temperature of BZTO get lower. TheDielectric constant of BMZTO decrease with the increase of the doping of MgO. TheDielectric constant of BMZTO with the same MgO content increase with prolonging ofheat preservation time. The Loss Tangent is lower than0.25. The Loss Tangent ofBMZTO with the same MgO content increase with the higher temperature. Theprolonging of heat preservation time and the increase of MgO content is good to the graingrowth.（4）The simulation result shows that the doping content of divalent cation, such asCa²⁺,Mg²⁺,in BaTiO₃,should be lower than20%. the doping content of tetravalent cation,such as Zr⁴⁺,Ce⁴⁺,Sn⁴⁺, in BaTiO₃,is lower,the effect is better. When the rare earthelements such as Y³⁺,Dy⁴⁺, dope BaTiO₃, the content of the rare earth elements should be lower while the content of the rare earth elements substitute position A as a certainamount, and the content should be higher while the content of the rare earth elementssubstitute position B as a certain amount.