Raman spectroscopy in pure and doped zinc ferrites nanoparticles

Abstract

Raman spectroscopy was applied on nanostructured ZnFe2O4 system in order to correlate its structural, chemical, and vibrational properties to the functional behaviour, in view of the high sensitivity of the Raman probe to the cationic order in iron oxides. In particular we investigated pure and Ga/Mg doped zinc ferrite nanoparticles synthesised by co-precipitation route by means of Raman spectroscopy with a particular focus on the correlation between their structural and magnetic properties. We firstly studied the homogeneity of the samples at the micrometer scale and their stability under laser irradiation disregarding the presence of spurious iron oxides in favour of a highly defective external shell of the nanoparticles. This hypothesis was corroborated by varying the incident laser wavelength therefore changing the investigated volume. Furthermore, we estimated the inversion degree of the spinel structure finding good agreements with the trend of the magnetic features. All the evidence found through Raman spectroscopy are supported by the results obtained with X-Ray Powder Diffraction, Electron Paramagnetic Resonance and SQUID magnetometry.

Influence of samarium on the structural, magnetic, and gas sensing performance of cadmium zinc ferrites

“…All samples revealed narrow hysteresis loops that are nearly flat with flatness values ranging from 9.9 to 41.8, where the S-shaped hysteresis appears a little more pronounced in S4 sample with flatness 9.9. Similar flat loops were reported in literature for cadmium-zinc and zinc ferrites [46,47,64,97,98]. The magnetic analysis from figure 16 revealed very low coercivity H C and retentivity M r ranging between 4-17G and 0.6-3.9 memu/g, respectively.…”