Nanodimensional spinel NiFe2O4 and ZnFe2O4 ferrites prepared by soft mechanochemical synthesis

Abstract

NiFe2O4 and ZnFe2O4 ferrites have been prepared by soft mechanochemical synthesis. The formation of spinel phase and crystal structure of sintered powders were analyzed by X-ray diffraction, Raman spectroscopy, and transmission microscopy. In order to confirm phase formation and cation arrangement, Mössbauer measurements were done. Investigation of the magnetization as a function of magnetic field confirms an expected change of the degree of inversion in the spinel structure with the sintering. The electrical DC/resistivity/conductivity was measured in the temperature range of 298-423 K. Impedance spectroscopy was performed in the wide frequency range (100 Hz-10 MHz) at different temperatures.

Influence of Bi3+-doping on the magnetic and Mössbauer properties of spinel cobalt ferrite

“…45 The isomer shift (δ), quadrupole splitting (Δ), and hyperfine field (H f ) corresponding to the tetrahedral (A) site and octahedral [B] sites can be obtained by a curve-fitting process (WinNormos software). 46 The δ values at both the (A) and [B] sites are the same for x = 0.0 and 0.1, indicating the s-electron distribution of the Fe 3+ ions could be insensitive to the Bi 3+ content. The δ value at the (A) site is increased for x = 0.2, while at the [B] site it is decreased with increasing nonmagnetic Bi 3+ content, which can be explained through the bonding nature of Fe 3+ with Co 2+ and Bi 3+ at both sites.…”

Raman spectra of Ni1‐XZnXFe2O4 nanopowders

“…Figure shows the Raman spectra of Ni 1‐x Zn x Fe 2 O 4 (x = 0, 0.25, 0.4, 0.5, 0.6, 0.75, 1) ferrite nanopowders obtained at room temperature in the region from 50 to 2,000 cm −1 . Here, for comparison, also shows Raman spectra of Fe 3 O 4 , NiFe 2 O 4 and ZnFe 2 O 4 at 300 K published in the papers …”

“…Raman spectra Ni 1‐x Zn x Fe 2 O 4 ferrites. Here, x = 0.0, 0.25, 0.4, 0.5, 0.6, 0.75, 1.0; A 1g ; F 2g ; E, symmetry of oscillations; Fe 3 O 4 * and NiFe 2 O 4 * from Graves et al; and ZnFe 2 O 4 * from Lazarevic et al x‐axes, wavenumber/cm −1 ; y‐axes, Raman intensity…”

Spectroscopy investigation of nanostructured nickel–zinc ferrite obtained by mechanochemical synthesis

“…Deconvolution of measured spectra allows one to conclude that all complex bands in the spectra are made of individual peaks with the intensities that vary from spectrum to spectrum. In order to determine the origin of the peaks, we have compared the Raman spectra of previously investigated NiFe 2 O 4 and ZnFe 2 O 4 [24], with the spectrum of single phase NZF, Fig. 7.…”