Microwave-Enhanced Crystalline Properties of Zinc Ferrite Nanoparticles

Abstract

Two series of ZnFe2O4 mixed cubic spinel nanoparticles were prepared by a coprecipitation method, where a solution of Fe3+ and Zn2+ was alkalised by a solution of NaOH. While the first series was prepared by a careful mixing of the two solutions, the microwave radiation was used to enhance the reaction in the other series of samples. The effect of the microwave heating on the properties of the prepared particles is investigated. X-ray powder diffraction (XRD), 57Fe Mössbauer spectroscopy and magnetometry were employed to prove the cubic structure and superparamagnetic behavior of the samples. The particle size in the range of nanometers was investigated by a transmission electron microscopy (TEM), and the N2 adsorption measurements were used to determine the BET area of the samples. The stoichiometry and the chemical purity were proven by energy dispersive spectroscopy (EDS). Additionally, the inversion factor was determined using the low temperature Mössbauer spectra in the external magnetic field. The microwave heating had a significant effect on the mean coherent length. On the other hand, it had a lesser influence on the size and BET surface area of the prepared nanoparticles.

Zinc Ferrite Nanoparticle Coatings on Austenitic Alloy Steel

“…The preparation of zinc ferrite nanoparticles was carried out according to the protocol that was published in our previous article [31]. The details of the preparation and characterization of the zinc ferrite nanoparticles can be found in the article [31]. The chemical compounds ZnCl 2 (p.a.…”

“…The broadened diffraction peaks and the Fd-3m structure confirmed the presence of the nanoscaled zinc ferrite. The doublet is a characteristic spectral component of non-magnetic iron compounds, including superparamagnetic nanoparticles [31].…”

“…The transmission Mössbauer spectroscopy was employed to exclude the formation of any amorphous phases and to monitor any changes in a close proximity of the Fe atoms. The fitting model for the room-temperature Mössbauer spectra included a singlet for the austenitic stainless steel and a doublet for the zinc ferrite (Figure 11a) [11,31]. The presented transmission Mössbauer spectra exhibited significant changes in the doublet's quadrupole splitting and full-width at half maximum (FWHM) (Table 2).…”

“…The first preliminary study was based on the synthesis of zinc ferrite under different conditions [31]. The synthetic procedure is used with identical synthetic parameters.…”