Tunable Magnetic and Electrical Properties of Cobalt and Zinc Ferrites CO1-XZnXFe2O4 Synthesized by Combustion Route

Abstract

Co and Zn ferrites with general formula CO 1-X Zn X Fe 2 O 4 (x = 0; 0,2 and 0,8) were synthesized by combustion reaction method, using urea as fuel. The structure of inverse-spinel-type ferrite were characterized through XRD using Rietveld refinement method to identify, quantify phases and determine lattice parameters. The crystallites had mean size of 37,33 nm, 43,66 nm and 51.88 nm with the increment of Zn 2+ , respectively. Samples were sintered in a resistive oven at 900 °C for 3 hours. Analysis by SEM indicated that the particles have irregular sizes and high concentration of open pores. The magnetic properties were measured using a vibrating sample magnetometer (VSM), through which a decrease in the magnetization variation was observed as the non-magnetic Zn 2+ concentration increases. The permittivity and loss tangent were determined using vector network analyzer equipment, permittivity increases with the increase of zinc concentration and the tangent loss measurements were small for all ferrites synthesized in this work.

Effect of pH Value on Synthesis and Properties of Zinc Cobalt Ferrite Nano Powders Prepared via Co-Precipitation Method

“…The XRD patterns of the synthesize samples at 750 °C for 2 hours are shown in Figure 2: [8] who reported that at pH=8 and at pHs above 11, some Fe2O3 and Zn (OH)2 impurities are present in the product, respectively. However, the appearance of higher backgrounds at pHs 8 and 14 than other samples may be attributed to the presence of glass or crystalline phases that were not observed by XRD analysis.…”

“…Due to this and achieving various properties such as magnetic permeability, coercive force, anisotropy constant, saturation magnetization (Ms), mechanical stiffness, physical and chemical stability, the range of use of these materials is varied. Accordingly, much research has been done on the doping effect of different 2/3 valent elements inside the ferrite structures on the synthesis and magnetic properties [5][6][7][8][9][10][11][12][13][14][15]. Among them, cobalt ferrite is interested due to properties such as high magnetic permeability, high coercive force (HC) (≥50 KOe), good saturation magnetization (MS) (80 emu/gr), mechanical hardness and excellent physical and chemical stability.…”

“…There are a number of methods for preparing magnetic nanoparticles (gaseou, solidous and liquidous phase synthesis). Although uniform nanoparticles have been synthesized using some of these methods, precise control of their size, shape and surface is generally challenging [8,18,19].…”

“…. In addition, according to Wuhlfarth's theory, anisotropic constant (K) and magnetic moment (nB) for the formula unit are obtained by Equations(3)(4)(5)(6)(7)(8) and(3)(4)(5)(6)(7)(8)(9) [4,16,39]:…”

Structural and Dielectric Evolution of Cobalt Ferrite Nanoparticles for Microwave Applications

“…Careful observation on the FTIR spectra shown in Figure 3 shows an absorption peak at 729cm -1 corresponding to intrinsic stretching vibrations of metal at the tetrahedral site, whereas the lowest band, observed in the range of 400-300cm -1 , is due to the octahedralmetal stretching [12]. Co 2+ ions usually occupy octahedral-site, while Fe 3+ ions has the tendency to occupy both octahedral and tetrahedral sites [13]. Further observations shows strong absortions peaks at 2941, 1721 and 1167 cm -1 wavelengths for the 1100 0 C sintered sample.…”