Effect of Fe3O4 addition on dielectric properties of LaFeO3 nano-crystalline materials synthesized by sol-gel method

International Symposium on Current Progress in Functional Materials

Laysandra, H.^1 ; Triyono, D.^1

Department of Physics, Faculty of Mathematics, Natural Sciences Universitas Indonesia, Kampus UI Depok, Depok

16424, Indonesia^1

关键词: Bode plots;    Colossal dielectric constant;    Dielectrical properties;    Impedance spectroscopy;    Nanocrystallines;    Nyquist;    Parallel plates;    Second phase;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/188/1/012039/pdf
DOI  :  10.1088/1757-899X/188/1/012039

来源: IOP

【 摘 要 】

Dielectric properties of nano-crystalline material LaFeO3.xFe3O4with x = 0, 0.1, 0.2, 0.3, and 0.4 at.% have been studied by impedance spectroscopy method. LaFeO3was synthesized by sol-gel method resulting nano-particle. Then, it was mixed with Fe3O4powder. The mixture powder was pressed to form pellet and then sintered at 1300°C for 1 h to form nano-crystalline of LaFeO3.xFe3O4. X-ray diffraction characterization at room temperature for all samples show two phases i.e. perovskite LaFeO3(orthorhombic) as a main phase and Fe3O4(cubic) as second phase. It is found that the crystallite size of main phase increases with addition of Fe3O4until 0.3 at.%. The electrical properties as a function of temperature (300-500 K) and frequency (100 Hz - 1 MHz) are presented in Nyquist and Bode plots. It is observed that from equivalent circuit and their parameters, dielectrical properties are contributed by grain and grain boundary. The dielectric constant, ′ were calculated by parallel plate method and their values reach up to 107exhibiting typical colossal dielectric constant (CDC) material like behavior.