Regulation on the non-ohmic properties of CaCu₃Ti₄O₁₂ ceramics material by yttriumion doping on calcium

The polycrystalline Ca_(1-x)Y_xCu₃Ti₄O₁₂(x=0,0.005,0.010,0.015,0.020,0.030,0.040) ceramics samples were prepared by traditional solid-state reaction method. The microstructure and nonohmic properties were characterized by X-ray diffraction,scanning electron microscope and the high-voltage digital source-meter. The effect mechanism of the variation in grain boundary barrier on the non-ohmic properties was also discussed. The results presented that there was no phase transition in Y³⁺-doped CaCu₃Ti₄O₁₂ samples,while the grain growth was related to the doping content. Both the density and chemical environment in grain boundary of samples were influenced by doping. The non-ohmic properties of CaCu₃Ti₄O₁₂ ceramics material were modified by Y³⁺ doping,and both non-linear coefficient and breakdown voltage were apparently enhanced by doping with the appropriate content(x=0.010~0.020).