Structural, magnetic and electrical properties of the lithium ferrite obtained by ball milling and heat treatment

Abstract

The physical properties of ferrites are very sensitive to microstructure, which in turn critically depends on the manufacturing process. Lithium ferrite is synthesized by milling process. The powder was annealed at four different temperatures 600, 800, 1,000 and 1,200°C. The powder annealed at 600°C has the spinel structure with some of a-Fe 2 O 3 , while the powders annealed at C800°C formed in single-phase cubic spinel structure. Particle size of lithium ferrite is in the range of 26-70 nm, and is dependent on the annealing temperature. The saturation magnetization increased from 22 to 85 emu/g and the coercivity decreases from 124 to 4 Oe with increase in the annealing temperature. The dielectric constant (e'), dielectric loss (tan d) and ac conductivity (r ac ) were measured at room temperature as a function of frequency. The results of dielectric properties were explained in terms of Koops phenomenological theory.

Electrical Conduction Mechanism and Dielectric Properties of Spherical Shaped Fe3O4 Nanoparticles Synthesized by Co-Precipitation Method

“…Koop’s theory was used to describe relationship between frequency and AC conductivity for different ferrites. According to this theory, in a low frequency region, grain boundaries with high resistance are responsible for constant conductivity, whereas in a high frequency region, the increase of the AC conductivity value is associated with grains with much higher conductivity than grain boundaries [ 15 ]. Maxwell-Wagner model is generally used to describe the polarization of grain boundaries in the low frequency region, and is applied to all inhomogeneous materials, such as multiphase materials and materials with large amount of interfaces and defects [ 16 , 17 , 18 ].…”

Synthesis and characterization of biopolymer protected zinc sulphide nanoparticles

“…According to Rezleseu model [39] such type of peak is obtained when the frequency of charge hopping between different ions exactly matches with the frequency of the external applied field. The condition for maximum tan d is given by the relation [40].…”

Cavity magnon polaritons with lithium ferrite and three-dimensional microwave resonators at millikelvin temperatures

“…One particular candidate is the single-phase crystal Lithium Ferrite (LiFe) of empirical formula a) Electronic mail: michael.tobar@uwa.edu.au Li 0.5 Fe 2.5 O 4 [20][21][22][23][24] , which belongs to the cubic spinel ferrites family with properties competitive with YIG 23,24 . LiFe belongs to the class of soft magnets with square magnetic hysteresis loops, large magnetization and strong anisotropy.…”