Small Rb⁺ doping in CaCu₃Ti₄O₁₂-A possible approach to reduce dielectric loss

Abstract

Ca_1−xRb _xCu₃Ti₄O₁₂ (x=0, 0.01, 0.02 and 0.03) ceramics were synthesized by the sol-gel method. Doping Rb⁺ reduces dielectric loss, which reaches minimum when x=0.02. By measuring properties of electrical conduction, larger leakage current density and height of grain-boundary Schottky potential barrier (ϕ_B) were found in the doped samples, and ϕ_B became maximum when x=0.02. These results are attributed to the increase in the amount of oxygen vacancies and the formation of Cu-rich/Ti-poor grain-boundary layers, and it can be concluded that the dielectric loss in CCTO ceramic can be reduced by manipulating the composition and electrical properties of grain boundary.

Keywords

CaCu₃Ti₄O₁₂ / dielectric constant / dielectric loss / electrical conduction

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