Mössbauer, Raman, and Magnetoresistance Study of Aluminum-Based Iron Oxide Thin Films

Abstract

Thin films of Al-based hematite iron oxide were synthesized by spray pyrolysis in aqueous medium onto the glass microslides. The compact and homogeneous distribution of grains (spindle-shaped hematite nanostructures) with varying sizes has been observed in surface morphological studies. The room temperature Mössbauer study has been carried out to monitor the local environment around Fe cations and valence state of Fe ions. Mössbauer and micro-Raman (low temperature) results suggest that oxygen vacancies cause cation redistribution between the interstitial sites resulting in magnetic ordering. The variation of magnetoresistance in low magnetic field (<3 kOe) is also reported.

Sustainable preparation of sunlight active α-Fe2O3nanoparticles using iron containing ionic liquids for photocatalytic applications

“…Further a decrease in value of quadrupole splitting (D) with the extension of alkyl chain length of MILs indicates increase in distortions from cubic structure due to surface effects on smaller particles. 54 The values of isomer shi (d) are consistent with literature report of hematite and indicates that Fe 3+ is in high spin state. 55 Along with a sextet, the presence of small central doublet indicates the superparamagnetic nature of synthesised NPs.…”

A highly selective Raney Fe@HZSM-5 Fischer–Tropsch synthesis catalyst for gasoline production: one-pot synthesis and unexpected effect of zeolites

“…0.33 mm s À1 and 50.5 T is resolved. 21 For R-Fe@HZSM-5, there is a superparamagnetic doublet with an IS of 0.33 mm s À1 and a quadrupole splitting (QS) of 0.79 mm s À1 attributable to high-spin Fe(III) in a distorted octahedral site, 22 which probably originated from the Fe species incorporated in HZSM-5 (Fig. 2d).…”

Revealing the atomistic origin of the disorder-enhanced Na-storage performance in NaFePO4 battery cathode

“…In contrast to the two weak peaks in this region for the olivine-type NaFePO 4 , three strong peaks at 217, 275 and 390 cm −1 appears for the maricite-type one. This differences should be ascribed to the different FeO 6 connecting patterns: corner sharing in olivine-type phase and bridge sharing in maricite-type phase [50][51][52]. Upon only 5 hrs milling (Fig.S10), the characteristic peak at 390 cm −1 disappears.…”