Study On Piezoelectric Properties Of La³⁺ Ce³⁺ Doped BT-BZ-CT Ceramics

The dielectric ceramics with BaTiO₃-BaZrO₃-CaTiO₃?BT-BZ-CT?as the main phase have high dielectric constant and good electrical properties such as ferroelectric and piezoelectric.BaTiO₃-BaZrO₃-CaTiO₃ ceramics were prepared by traditional solid phase sol-gel method.By varying the amount of CaTiO₃ and doping different degrees of La³⁺and Ce³⁺ion,the crystal structure of the samples were investigated.The Research shows:The solid phase dielectric loss is small and stable?tan?is between 0.005⁰.01?,and the liquid phase loss is large?tan?is between 0.01⁰.02?.When x=0.14,the piezoelectric coefficient of the solid phase method is 95 pC/N,and the residual polarization is 5.01?c/cm².The coercive field is 2.81 kV/cm,the piezoelectric coefficient of the liquid phase method is 132 pC/N,the residual polarization is 5.12?c/cm²,and the coercive electric field is 1.33 kV/cm.Small coercive field was beneficial to the polarization of piezoelectric ceramics.The increase of sintering temperature is beneficial to the complete grain growth,but when the sintering temperature is too high,small crystal grains will be precipitated at the grain boundary of the crystal,which will affect the dielectric,piezoelectric and ferroelectric properties of the sample.When the sintering temperature re aches 1400^oC,the ceramic sample has complete grain growth.The dielectric constant and ferroelectric dispersion phase transition of La³⁺and Ce³⁺doped BT-BZ-CT based ceramic samples increased,which affected the piezoelectric and ferroelectric properties.The dielectric constant and the ferroelectric dispersion phase transition of the La³⁺doped BT-BZ-CT ceramic sample were significantly improved,and the dielectric constant was 6800.The piezoelectric coefficient of the sample doped with Ce³⁺was remarkably improved by a piezoelectric coefficient of 249 pC/N.The ferroelectricity of the ceramic sample is also improved by the addition of La³⁺and Ce³⁺,and the repolarization intensity of the pattern incorporating La³⁺is higher at 8.3?c/cm².Figure 54;Table 18;Reference 66.