Effect Of Doping On The Structure And Properties Of Electronic Materials BaTi_0.85Zr_0.15O₃

Dielectric constant is the most important factor on describing the properties of electricity and dielectric material[1]. Pure BaTiO3 owns very high dielectric constant around Curie Point, but decreases rapidly when deviating Curie Point. We can make the temperature down if adding modified materials. Now we take Zr4+ ion as an example, though Zr4+ ion has the same chemical bond as Ti4+ ion, the bigger ion radius of Zr4+ leads to decrease the Curie Point.This paper takes BaTi0.85Zr0.15O3 as original material, doping separately different quantity of three rare earth metal oxide Yb2O3,Dy2O3 and Ho2O3, then adding SiO2,MnO2 and ZnO. These powder changes into BaTi0.85Zr0.15O3 dielectric ceramic through mingling, shaping and sintering(at 1200℃). We use CM7115 A to measure the capacitance as the temperature changes. At last, we obtain the dielectric constants at different temperature by converting. On the other hand, the structure analysis of ceramics was carried out by SEM after polishing.The result shows that rare earth dopant makes the dielectric properties of ceramics better. In this experience, BaTi0.85Zr0.15O3 ceramics with doping 0.2% Yb2O3 posses very high dielectric constant at normal temperature. The dielectric constant decreases gradually as the temperature increases ranging from 3333 at 20℃ to 1543 at 120℃, so we can obtain the best dielectric properties at normal temperature; on the other hand, from SEM we can see that BaTi0.85Zr0.15O3 with doping Yb2O3 has larger crystal, and BaTi0.85Zr0.15O3 with doping 0.1% Ho2O3 owns the most well-distributed little crystal.