中国物理B ›› 2016, Vol. 25 ›› Issue (12): 128201-128201.doi: 10.1088/1674-1056/25/12/128201

• INTERDISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY • 上一篇    下一篇

Electrical and dielectric properties of Na1/2La1/2Cu3Ti4O12 ceramics prepared by high energy ball-milling and conventional sintering

H Mahfoz Kotb, Mohamad M Ahmad   

  1. 1. Department of Physics, College of Science, King Faisal University, Al-Hassa 31982, Saudi Arabia;
    2. Department of Physics, Faculty of Science, Assiut University, Assiut 71516, Egypt;
    3. Department of Physics, Faculty of Science, Assiut University, The New Valley, El-Kharga 72511, Egypt
  • 收稿日期:2016-07-03 修回日期:2016-08-23 出版日期:2016-12-05 发布日期:2016-12-05
  • 通讯作者: H Mahfoz Kotb, Mohamad M Ahmad E-mail:hkotb@kfu.edu.sa;mmohamad@kfu.edu.sa

Electrical and dielectric properties of Na1/2La1/2Cu3Ti4O12 ceramics prepared by high energy ball-milling and conventional sintering

H Mahfoz Kotb1,2, Mohamad M Ahmad1,3   

  1. 1. Department of Physics, College of Science, King Faisal University, Al-Hassa 31982, Saudi Arabia;
    2. Department of Physics, Faculty of Science, Assiut University, Assiut 71516, Egypt;
    3. Department of Physics, Faculty of Science, Assiut University, The New Valley, El-Kharga 72511, Egypt
  • Received:2016-07-03 Revised:2016-08-23 Online:2016-12-05 Published:2016-12-05
  • Contact: H Mahfoz Kotb, Mohamad M Ahmad E-mail:hkotb@kfu.edu.sa;mmohamad@kfu.edu.sa

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摘要：

We report on the measurements of the electrical and dielectric properties of Na1/2La1/2Cu3Ti4O12 (NLCTO) ceramics prepared by high energy ball-milling and conventional sintering without any calcination steps. The x-ray powder diffraction analysis shows that pure perovskite-like CCTO phase is obtained after sintering at 1025℃-1075℃. Higher sintering temperatures result in multi-phase ceramics due to thermal decomposition. Scanning electron microscope observations reveal that the grain size is in a range of ~3 μm-5 μm for these ceramics. Impedance spectroscopy measurements performed in a wide frequency range (1 Hz-10 MHz) and at various temperatures (120 K-470 K) are used to study the dielectric and electrical properties of NLCTO ceramics. A good compromise between high ε' (5.7×103 and 4.1×103 at 1.1 kHz and 96 kHz, respectively) and low tanδ (0.161 and 0.126 at 1.1 kHz and 96 kHz, respectively) is obtained for the ceramic sintered at 1050℃. The observed high dielectric constant behavior is explained in terms of the internal barrier layer capacitance effect.

关键词: ceramics, sintering, dielectric loss and relaxation, electrical

Abstract:

We report on the measurements of the electrical and dielectric properties of Na1/2La1/2Cu3Ti4O12 (NLCTO) ceramics prepared by high energy ball-milling and conventional sintering without any calcination steps. The x-ray powder diffraction analysis shows that pure perovskite-like CCTO phase is obtained after sintering at 1025℃-1075℃. Higher sintering temperatures result in multi-phase ceramics due to thermal decomposition. Scanning electron microscope observations reveal that the grain size is in a range of ~3 μm-5 μm for these ceramics. Impedance spectroscopy measurements performed in a wide frequency range (1 Hz-10 MHz) and at various temperatures (120 K-470 K) are used to study the dielectric and electrical properties of NLCTO ceramics. A good compromise between high ε' (5.7×103 and 4.1×103 at 1.1 kHz and 96 kHz, respectively) and low tanδ (0.161 and 0.126 at 1.1 kHz and 96 kHz, respectively) is obtained for the ceramic sintered at 1050℃. The observed high dielectric constant behavior is explained in terms of the internal barrier layer capacitance effect.

Key words: ceramics, sintering, dielectric loss and relaxation, electrical

中图分类号:  (Ceramics in electrochemistry)

  • 82.45.Xy
81.20.Ev (Powder processing: powder metallurgy, compaction, sintering, mechanical alloying, and granulation) 77.22.Gm (Dielectric loss and relaxation) 84.37.+q (Measurements in electric variables (including voltage, current, resistance, capacitance, inductance, impedance, and admittance, etc.))