Characterisation of iron oxide nanoparticles by Mössbauer spectroscopy at ambient temperature

Joos, Alexander; Rümenapp, Christine; Wagner, F. E.; Gleich, Bernhard

doi:10.1016/j.jmmm.2015.09.060

Cited by 39 publications

(20 citation statements)

References 37 publications

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“…δ values given in Table 2 for sextet 2 is 0.10 mm/s and for Q is − 0.04 mm/s which shows valence state of iron is +3. Similar values are also observed by Joos et al [42] for Fe 3 O 4 nanoparticles; they ascribed these values to tetrahedral Fe +3 . δ values for Fe NCs-6 given in Table 3 for sextet 3 and 4 are 0.15 mm/s and 0.20 mm/s shows Fe +3 in Fe 2 O 3 .…”

Section: Resultssupporting

confidence: 89%

Structural characterization of self-assembled chain like Fe-FeOx Core shell nanostructure

et al. 2019

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One of the big challenge of studying the core-shell iron nanostructures is to know the nature of oxide shell, i.e., whether it is γ-Fe2O3 (Maghemite), Fe3O4 (Magnetite), α-Fe2O3 (Hematite), or FeO (Wustite). By knowing the nature of iron oxide shell with zero valent iron core, one can determine the chemical or physical behavior of core-shell nanostructures. Fe core-shell nanochains (NCs) were prepared through the reduction of Fe3+ ions by sodium boro-hydride in aqueous solution at room atmosphere, and Fe NCs were further aged in water up to 240 min. XRD was used to study the structure of Fe NCs. Further analysis of core-shell nature of Fe NCs was done by TEM, results showed increase in thickness of oxide shell (from 2.5, 4, 6 to 10 nm) as water aging time increases (from 0 min, 120 min, 240 min to 360 min). The Raman spectroscopy was employed to study the oxide nature of Fe NCs. To further confirm the magnetite phase in Fe NCs, the Mössbauer spectroscopy was done on Fe NCs-0 and Fe NCs-6. Result shows the presence of magnetite in the sample before aging in water, and the sample after prolonged aging contains pure Hematite phase. It shows that prolonged water oxidation transforms the structure of shell of Fe NCs from mixture of Hematite and Magnetite in to pure hematite shell. The Magnetic properties of the Fe NCs were measured by VSM at 320 K. Because of high saturation magnetization (Ms) values, Fe NCs could be used as r2 contrasts agents for magnetic resonance imaging (MRI) in near future.

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Section: Resultssupporting

confidence: 89%

Structural characterization of self-assembled chain like Fe-FeOx Core shell nanostructure

et al. 2019

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“…In this process,

ions are oxidized to Fe 3+ in octahedral sites [ 89 , 90 ], which leads to the decrease in the intensity of the IVCT peak [Fe 2+ ] t2g →[Fe 3+ ] eg . Furthermore, it was shown in [ 91 , 92 ] using the Mössbauer spectroscopy that the oxidation of magnetite to maghemite is accompanied by a decrease in the fraction of trivalent iron ions in tetrahedral sites. It is assumed that this effect leads to a decrease in the intensity of the intersublattice charge-transfer transition (Fe 3+ ) t2 →[Fe 3+ ] t2g with the decrease in particle size.…”

Section: Resultsmentioning

confidence: 99%

Magnetic and Magneto-Optical Oroperties of Iron Oxides Nanoparticles Synthesized under Atmospheric Pressure

et al. 2020

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Magnetite nanoparticles were synthesized by a simple thermal decomposition process, involving only iron (III) nitrate nonahydrate as a precursor, and hexadecylamine as a solvent and stabilizer at reaction temperatures varied from 200 to 380 °C. The results of the structural analysis showed that the average crystallite size depends on the reaction temperature and increases from 4.8 to 13.3 nm. The behavior of the coercivity indicates that all synthesized samples are single domain; herewith, it was found that the critical size corresponding to the transition to the superparamagnetic state at room temperature is about 9 nm. The effect of the reaction temperature on changes in the saturation magnetization was studied. It was found that the size effect in the MCD spectra is observed for the IVCT transition and one ISCT transition, and the influence of the reaction temperature on the change in the MCD spectra was discussed.

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“…This was a remarkable achievement, considering that normally NPs smaller than 15 nm are affected by superparamagnetic relaxation, which hinders their characterization by Mössbauer spectroscopy. 282 In another work, β-FeOOH NPs were prepared in a microemulsion system with the use of a non-ionic surfactant. Several characterization techniques were employed to study the properties of the product, and 57 Fe Mössbauer spectra showed that the magnetic structure transformed below 150 K, and two kinds of Fe-O octahedra were present in the lattice of the modified β-FeOOH NPs.…”

Section: Characterization Methods For Magnetic Nanostructuresmentioning

confidence: 99%

Characterization techniques for nanoparticles: comparison and complementarity upon studying nanoparticle properties

2018

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Nanostructures have attracted huge interest as a rapidly growing class of materials for many applications. Several techniques have been used to characterize the size, crystal structure, elemental composition and a variety of other physical properties of nanoparticles. In several cases, there are physical properties that can be evaluated by more than one technique. Different strengths and limitations of each technique complicate the choice of the most suitable method, while often a combinatorial characterization approach is needed. In addition, given that the significance of nanoparticles in basic research and applications is constantly increasing, it is necessary that researchers from separate fields overcome the challenges in the reproducible and reliable characterization of nanomaterials, after their synthesis and further process (e.g. annealing) stages. The principal objective of this review is to summarize the present knowledge on the use, advances, advantages and weaknesses of a large number of experimental techniques that are available for the characterization of nanoparticles. Different characterization techniques are classified according to the concept/group of the technique used, the information they can provide, or the materials that they are destined for. We describe the main characteristics of the techniques and their operation principles and we give various examples of their use, presenting them in a comparative mode, when possible, in relation to the property studied in each case.

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Characterisation of iron oxide nanoparticles by Mössbauer spectroscopy at ambient temperature

Cited by 39 publications

References 37 publications

Structural characterization of self-assembled chain like Fe-FeOx Core shell nanostructure

Structural characterization of self-assembled chain like Fe-FeOx Core shell nanostructure

Magnetic and Magneto-Optical Oroperties of Iron Oxides Nanoparticles Synthesized under Atmospheric Pressure

Characterization techniques for nanoparticles: comparison and complementarity upon studying nanoparticle properties

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