Electrical and dielectric properties of Na_(1/2)La_(1/2)Cu_3Ti_4O_(12) ceramics prepared by high energy ball-milling and conventional sintering

作     者：H Mahfoz Kotb Mohamad M Ahmad 

作者机构：Department of PhysicsCollege of ScienceKing Faisal University Department of PhysicsFaculty of ScienceAssiut University 

出 版 物：《Chinese Physics B》 (中国物理B（英文版）)

年 卷 期：2016年第25卷第12期

页      面：474-480页

核心收录：

学科分类：08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 

基　　金：King Faisal University for financial support under grant No. DSR-160162 

主　　题：ceramics sintering dielectric loss and relaxation electrical 

摘      要：We report on the measurements of the electrical and dielectric properties of Na1/2La1/2Cu3Ti4O12 （NLCTO） ce- ramics 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 ×10^3 and 4.1 × 10^3 at 1.1 kHz and 96 kHz, respectively） and low tan δ （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.