Structural, AC conductivity, dielectric behavior and magnetic properties of Mg-substituted LiFe5O8 powders synthesized by sol–gel auto-combustion method

Abstract

Magnesium-substituted lithium ferrite powders (Li 1-x Mg 2x Fe 5-x O 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 2? ion content. The microstructure of the formed powders was Mg concentration dependent. Increasing the Mg 2? ion ratio was found to inhibit the grain growth of the formed ferrite. The AC electrical conductivity of Mg 2? ion substituted lithium ferrite samples was raised with increasing the concentration of Mg 2? ions as the result of increasing the hopping of electrons between Fe 2? and Fe 3? ions. Meanwhile, dielectric constant (e 0 ) was diminished with increasing the frequency of external electric field as well as increasing the temperature and concentration of Mg 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 2? molar ratio of 0.4 annealed at 800°C for 2 h.

A Simple, Quick and Eco-Friendly Strategy of Synthesis Nanosized α-LiFeO2 Cathode with Excellent Electrochemical Performance for Lithium-Ion Batteries

“…74-2283, a = 4.156 Å). When the temperature rises to 350 °C, there is an impurity phase, which can be attributed to spinel LiFe 5 O 8 [ 20 , 21 ]. This result agrees with the reported result that the LiFe 5 O 8 impure phase appears after high temperature sinter process [ 15 ].…”

Impact of ZrO2 additive on the microstructure, magnetic properties, and temperature dependence of the initial permeability of LiTiZn ferrite ceramics

“…High synthesis temperatures lead to the volatility of lithium and oxygen at temperatures above 1000 °C resulting in the magnetic properties deterioration, and dielectric losses increasing in ferrite ceramics [4]. Several wet chemical methods, including self-combustion [5,6], hydrothermal ball milling [7][8][9], the method of citrate precursor [10], and sol-gel synthesis [11,12], have been developed. These methods are utilized to obtain lithium ferrite at lower temperatures, as well as to minimize side phase inclusions and defects featured to ceramic technology.…”

Facile Synthesis of Flowerlike LiFe5O8 Microspheres for Electrochemical Supercapacitors

“…Recently, there are many kinds of synthesis methods for LFO, such as the thermal decomposition method, the conventional ceramic method, the sol–gel autocombustion method, etc. Although these methods have many advantages, they only fit to prepare bulk LFO particles.…”

“…At present, Kim and Manthiram 29 reported that LFO had a discharge capacity of ∼140 mAh g −1 in the range of 1.5−4.3 V, demonstrating an excellent cycling retention. Similarly, Lee et al 30 Recently, there are many kinds of synthesis methods for LFO, such as the thermal decomposition method, 31 the conventional ceramic method, 32 the sol−gel autocombustion method, 33 find a novel method that can fabricate the flowerlike porous LFO particles. The etching method 34,35 is an excellent synthesis method, which attracts much attention, because it possesses a simple process, short production cycle, no waste residue, and environmental friendliness.…”