Effects of Er₂O₃ dopant on dielectric properties of BaTiO₃ ceramics

BaTiOs ceramics doped with various qualities of Er₂O₃ were prepared (the additive mol fraction were 0.001, 0.002, 0.003, 0.005, 0.007 respectively) through Sol-Gel method. Their resistivity at room temperature and the dielectric properties were researched. It is found that the addition of Er₂O₃ can make the resistivity of Ba-TiO₃ ceramics decline. The resistivity increases with increase in Er₂O₃ additive mol fraction at first and reaches the highest at 0.003, and then begins to decrease, when the Er₂O₃ additive mol fraction is 0.007, the resistivity is the smallest, which declines from 2.6 TΩ · m to 18 GΩ · m, this rule is different from that of La, Ce, Nd, Sm dopant. The addition of Er₂O₃ also can make the dielectric properties of BaTiO₃ ceramics change evidently under different additive mol fraction and different frequency. When the additive mol fraction of Er₂O₃ is 0.001 and 0.002, the dielectric properties and the frequency characteristics are improved obviously. The Curie-temperature increases to 130.9 °C by addition of Er₂O₃. The alternating conductance increases with the change of temperature, and reaches the highest at the Curie-temperature.