Abstract

CaCu₃Ti₄O₁₂ ceramics were prepared using a green solution-egg white method. A main phase of CaCu₃Ti₄O₁₂ is observed in the obtained powder and all sintered ceramics. The microstructure of all ceramics is studied. Their grain sizes are found to be in the range of 4–7 µm. Giant dielectric properties with low dielectric loss (tanδ ∼ 0.07) and large dielectric permittivity (ε′ ∼ 7000) are achieved in the sintered CaCu₃Ti₄O₁₂ ceramic. An impedance spectroscopy analysis confirms a heterogeneous microstructure in sintered CaCu₃Ti₄O₁₂ ceramics, consisting of highly resistive grain boundaries and semiconducting grains. Mixed Cu³⁺/Cu²⁺/Cu⁺ and Ti⁴⁺/Ti³⁺ phases are detected using X-ray photoelectron spectroscopy, confirming the presence of semiconducting grains.

中文翻译：

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绿溶液-鸡蛋白法测定CaCu 3 Ti 4 O 12的介电常数

摘要

CaCu ₃ Ti ₄ O ₁₂陶瓷采用绿色溶液-鸡蛋白法制备。在所得粉末和所有烧结陶瓷中观察到CaCu ₃ Ti ₄ O ₁₂的主相。研究了所有陶瓷的微观结构。发现它们的晶粒尺寸在4–7 µm的范围内。在烧结的CaCu ₃ Ti ₄ O ₁₂陶瓷中，具有低介电损耗（tanδ〜0.07）和大介电常数（ε′〜7000）的优良介电性能。阻抗谱分析证实了烧结的CaCu ₃ Ti ₄ O _12中的异质组织陶瓷，由高电阻的晶界和半导体晶粒组成。使用X射线光电子能谱检测混合的Cu ³⁺ / Cu ²⁺ / Cu ⁺和Ti ⁴⁺ / Ti ³⁺相，确认存在半导体晶粒。