57Fe Mössbauer spectroscopic study of nanostructured zinc ferrite

Abstract

Nanosize zinc ferrite particles, prepared by nitrate method, were investigated by XRD, TEM, 57 Fe Mössbauer spectroscopy and VSM. The average particle size in this system varies from 10 to 62 nm as the sintering temperature increases from 300 • C to 1,000 • C. The lattice parameters in this system are almost constant at a value of ∼8.41 Å. The Mössbauer spectra of all the sintered samples show a single doublet. The Mössbauer hyperfine parameters show little change with the change of sintering temperature. The doublets are ascribed to the presence of superparamagnetism in this system, which is also corroborated by the VSM measurements.

Synthesis and Characterization of Novel Phyto-Mediated Catalyst, and Its Application for a Selective Oxidation of (VAL) into Vanillin under Visible Light

“…The lattice constant (a = 8.365 ± 0.010 Å) was obtained from the slope of the linear fit to the experimental data. This value is consistent with the reported values of 8.34-8.41 Å [40].…”

“…The saturation magnetization (Ms) was obtained from a plot of M vs. 1/H in the high field range by extrapolating to 1/H = 0. Following the analysis in Mahmood's study [40], the slope of the straight line was used to determine the lower limit (Ds) of the particle diameter in the sample. Additionally, the upper limit of the particle diameter (Dl) was determined from the initial magnetic susceptibility using the analysis provided in the same reference.…”

Annealing effect on zinc nanoferrite particles synthesized by spray pyrolysis of polymer precursor

“…All the peaks in the pattern could arise from the cubic spinel structure of the sample. The average particle size and lattice parameters of the sample were estimated from the most intense peak (Table 3) [4,5]. The lattice parameters of the prepared samples are in good agreement with values reported earlier [5,6,9] and are found to be in the range of 8.4313-8.4519Å as the annealing temperature increases from 250 to 550…”

“…The peaks corresponding to the planes (220), (311), (222), (400), (422), (511), and (440) confirm the formation of the spinel structure of the ferrite [4,5]. However, the pyrolytic decomposition process of ferrite powders is a chemically complicated process in which many intermediate products can be formed.…”

Relaxation Phenomena in Nanostructured Zinc Ferrite

“…Further, a magnetization anomaly was observed in nanosize zinc ferrite synthesized by using the electrodeposition. 18 The existence of magnetic ordering at room temperature is believed to originate from geometrical frustration, 19,20 superparamgnetic state, 17,21 co-existence of ferrimagnetic and antiferromagnetic ordering. 22 The overall magnetic behavior of nanostructured zinc ferrite is similar to that obtained for substituted Fe 3+ ferrite system in that the antiferromagnetic order gives rise to ferrimagnetism via a spin-glass or local canting state.…”