Modified giant dielectric properties of samarium doped CaCu₃Ti₄O₁₂ ceramics

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• 作者：Prasit Thongbai ; Bundit Putasaeng ; Teerapon Yamwong ; Santi Maensiri
• 关键词：A. Ceramics ; C. X-ray diffraction ; D. Dielectric properties ; D. Electrical properties
• 刊名：Materials Research Bulletin
• 出版年：2012
• 出版时间：September, 2012
• 年：2012
• 卷：47
• 期：9
• 页码：2257-2263
• 全文大小：1013 K

文摘

Effects of Sm³⁺ substitution on the microstructure and dielectric properties of CaCu₃Ti₄O₁₂ ceramics were investigated. The grain size of CaCu₃Ti₄O₁₂ ceramics was greatly decreased by doping with Sm³⁺, resulting from the ability of Sm³⁺ to inhibit the grain growth rate. This result can cause a decrease in the dielectric constant (?¡ä) and loss tangent (tan ¦Ä) of CaCu₃Ti₄O₁₂ ceramics. Interestingly, high dielectric permittivity (?¡ä ¡« 10,863) and low loss tangent (tan ¦Ä ¡« 0.043 at 20 ¡ãC and 1 kHz) were observed in the Ca_0.925Sm_0.05Cu₃Ti₄O₁₂ ceramic. Nonlinear electrical properties of CaCu₃Ti₄O₁₂ ceramics were modified by doping with Sm³⁺. The dielectric relaxation behavior of Sm-doped CaCu₃Ti₄O₁₂ ceramics can be well ascribed based on the internal barrier layer capacitor model of Schottky barriers at the grain boundaries.