Microstructural and magnetic characterization of Ni0.5Zn0.5Fe2O4 ferrite nanoparticles

Abstract

The comprehensive study of the Ni0.5Zn0.5Fe2O4 ferrite nanopowder crystallized in the inverse spinel structure and synthesized by co-precipitation method is presented. The distribution of Fe 3+ cations among tetrahedral and octahedral sites was confirmed. The microstructural investigations revealed the presence of ultrafine grained structure with an average crystallites size in the range of 14 ÷ 20 nm. Raman and Fourier-Transform Infrared (FTIR) spectroscopy studies confirmed typical spinel structure with tetrahedrally and octahedrally iron occupancy as well as indicate co-associated iron-oxide phases considered as factors responsible for the structural disorder. The magnetic properties revealed the superparamagnetic behavior at the room temperature with estimated critical size of single domain particles about 63 nm. The analysis of saturation magnetization pointed to the spin canting phenomenon in the surface layer. The valuation of exchange coupling parameters based on the mean field theory calculation strengthened the conclusion about opposite magnetization arrangement between tetrahedral and octahedral magnetic sublattices.

Development of ferritization processing of galvanic waste involving the energy­saving electromagnetic pulse activation of the process

“…Available data on the mechanism of the ferritization process suggests a rather complex phase composition of the sediments obtained. The sediment may contain various modifications of oxides and oxyhydrates of ferrum, nickel, copper, and zinc, which by nature are ferromagnetic, but, due to the small dimensions, they demonstrate paramagnetic properties [17]. Our analysis of structural studies has revealed that samples from the G2 and G7 series of experiments, obtained under the thermal and electromagnetic pulse activation technique, are, respectively, characterized by the maximal content of ferrite phases with magnetic properties (≥89 %).…”

“…Samples from the G2 and G7 series contain crystals of irregular shape in a porous space. Such structures have good sorption capacity both for heavy metal ions and to organic matter, and thus can be successfully used to clean flush waste water from industrial production [17]. The results from experiments, given in Table 4, showed that for galvanic sludge the content of heavy metal ions in the leaching eluate does not meet the requirements by DSanPiN 2.2.7.029-99 and the EU Directive 86/278/EU in terms of MPC in soil.…”

Influence of neodymium substitution on structural, magnetic and spectroscopic properties of Ni–Zn–Al nano-ferrites

“…[37][38][39] In our case, the higher frequency absorption band y 1 is assigned for Fe 3+ -O intrinsic vibration of tetrahedral group in the range of 570 cm À1 and the lower frequency absorption band y 2 is attributed to that of the octahedral group near 405 cm À1 which is the ngerprint of Zn-Ni ferrites. 39,40 There are additional frequency band located near 1061 cm À1 corresponding to the O-H stretching vibrations. 41 It can be noted from the gure that the peaks intensity amplies with raising the Nd 3+ doping level.…”

Impact of Mg‐Zr substitution on the magnetic and microwave absorption properties of BaFe12‐2xMgxZrxO19 (0.25 ≤ x ≤ 1.5)

“…According to Figure 5A, BaFe 12 O 19 mainly consist of agglomeration micro and nanoparticles. The aggregation is a result of magnetic dipole‐dipole interaction between nanoparticles 24 . Besides, based on Figure 5B‐G, the addition of substitutions increases their concentration from 0.25 to 1.5 causing agglomeration to decrease forming small nanoparticles.…”