Study of NiFe₂O₄and ZnFe₂O₄Spinel Ferrites Prepared by Soft Mechanochemical Synthesis

Abstract

Two types of ferrites, NiFe 2 O 4 and ZnFe 2 O 4 were prepared by soft mechanochemical synthesis. XRD and Raman spectroscopy were used to characterize the ferrite samples. On the basis of magnetic measurements was confirmed that the degree of inversion changes after sintering. The conduction activation energy, E was determined by fitting the DC conductivity data with the Arrhenius relation. The effect of temperature on impedance parameters was studied using an impedance analyzer in a wide frequency range (100 Hz -10 MHz). It was observed that the impedance spectra of NiFe 2 O 4 and ZnFe 2 O 4 ferrites include both grain and grain boundary effects.

Domain size correlated magnetic properties and electrical impedance of size dependent nickel ferrite nanoparticles

“…The exponent φ describes the degree of capacitive nature of the component. [35][36][37] Now the total impedance of the RQ circuit without a series resistance can be written as…”

Mechanochemical Synthesis of Catalytic Materials

“…From a catalysis viewpoint, the possibilities of controlling composition, structure, valence, and morphology have made spinel systems suitable as catalysts in many different reactions, including NO x reduction, [102, 103] CO oxidation, [104] CO 2 reduction, [105] hydrogen evolution reaction (HER), [106] oxygen reduction reaction (ORR), [107] oxygen evolution reaction (OER), [108] and alcohol oxidation [109–110] . Spinel oxides based on Mg‐Al, Fe‐Co, Mg‐Fe, Ni‐Fe, Zn‐Fe, and Zn‐Al systems are the most important ones among the ternary oxides—together with the perovskite family—and can be fabricated by ball milling [111–119] . In general, the mechanochemical synthesis of spinel oxides is based on a bottom‐up approach, involving the ball milling of the oxide, oxyhydroxide, or hydroxide metal precursors at room temperature in air.…”

“…This is advantageous from the catalysis perspective. Spinel ferrites of other redox metals, such as Ni and Zn, have also been similarly synthesized via direct ball milling of hydroxide precursors [114, 119] …”

Mechanosynthesis of MFe2O4 (M = Co, Ni, and Zn) Magnetic Nanoparticles for Pb Removal from Aqueous Solution

“…In our samples, 1 and 2 frequencies were observed at 589 cm −1 for CoFe 2 O 4 , 596 cm −1 and 404 cm −1 for NiFe 2 O 4 , and 564 cm −1 and 428 cm −1 for ZnFe 2 O 4 (Figure 2). The replacement of (3) are due to symmetric and asymmetric bending of oxygen with respect to Fe (or M), respectively, and F 2g (2) is assigned to asymmetric stretching of Fe(M)-O bond, whereas F 2g (1) is attributable to translational movement of the whole tetrahedron [34].…”

“…Soft mechanochemical reactions usually employ surface hydroxyl groups, adsorbed, hydrated, or contained in a hydroxide. Mechanochemical derived precursors exhibit significantly higher reactivity and thus lower the calcination and sintering temperature [34].…”