Structural, AC conductivity, dielectric behavior and magnetic properties of Mg-substituted LiFe^sub 5^O^sub 8^ powders synthesized by sol-gel auto-combustion method

• Published in: Journal of materials science. Materials in electronics 2015-08, Vol.26 (8), p.6040
• Main Authors: El-shaarawy, M G, Rashad, M M, Shash, N M, Maklad, M H, Afifi, F A
• Format: Article
• Language: English
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-015-3181-2

Issue Title: Special Issue: Second Symposium of Renewable Energy and Sustainability: Research of Solar Materials in Mexico Magnesium-substituted lithium ferrite powders (Li^sub 1-x^Mg^sub 2x^Fe^sub 5-x^O^sub 8^ where x = 0.0-0.8) were prepared by sol-gel auto-combustion method. XRD profiles revealed that all compositions were single cubic ferrite structure for the precursors annealed at 800 °C for 2 h. The crystallite size was found to decrease whereas the lattice parameter was increased with increasing Mg^sup 2+^ ion content. The microstructure of the formed powders was Mg concentration dependent. Increasing the Mg^sup 2+^ ion ratio was found to inhibit the grain growth of the formed ferrite. The AC electrical conductivity of Mg^sup 2+^ ion substituted lithium ferrite samples was raised with increasing the concentration of Mg^sup 2+^ ions as the result of increasing the hopping of electrons between Fe^sup 2+^ and Fe^sup 3+^ ions. Meanwhile, dielectric constant ([straight epsilon]') was diminished with increasing the frequency of external electric field as well as increasing the temperature and concentration of Mg^sup 2+^ ions. Alongside, the formed crystalline magnesium substituted lithium ferrite had good magnetic properties. High saturation magnetization (78.7 emu/g) was attained by the formed ferrite sample at Mg^sup 2+^ molar ratio of 0.4 annealed at 800 °C for 2 h.