Structural–chemical transformations of α-Fe2O3 upon transport reduction

Murin, I. V.; Смирнов, В. М.; Voronkov, G. P.; Семенов, В. Г.; Поваров, В. Г.; Sinel'nikov, B. M.

doi:10.1016/s0167-2738(00)00748-7

Cited by 21 publications

(5 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Therefore both a low and a high oxygen pressure would lead to a non-equilibrium condition under which some intermediate phases of iron oxide with a non-stoichiometric composition and crystal defects were formed. Similar results were obtained by Murin et al during the oxidation of iron [11].…”

Section: X-ray Powder Diffraction and Mössbauersupporting

confidence: 91%

Combustion synthesis of zinc ferrite powders in oxygen

Zhao

Qiang

et al. 2004

Journal of Alloys and Compounds

View full text Add to dashboard Cite

Section: X-ray Powder Diffraction and Mössbauersupporting

confidence: 91%

Combustion synthesis of zinc ferrite powders in oxygen

Zhao

Qiang

et al. 2004

Journal of Alloys and Compounds

View full text Add to dashboard Cite

“…Thermally induced solid-state reductions of suitable Fe(III) phases towards magnetic Fe 3 O 4 and Fe particles have been investigated from the viewpoint of reduction mechanism and kinetics in various atmospheres (argon, helium, hydrogen, vacuum), particularly with Fe 2 O 3 as a precursor [70][71][72][73][74][75][76][77]. Two thermal reduction processes have been reported for the preparation of magnetite or alpha-Fe nanoparticles.…”

Section: Introductionmentioning

confidence: 99%

Novel solid-state synthesis of α-Fe and Fe₃O₄nanoparticles embedded in a MgO matrix

et al. 2006

View full text Add to dashboard Cite

Thermally induced reduction of amorphous Fe2O3 nanopowder (2–3 nm) with nanocrystalline Mg (∼20 nm) under a hydrogen atmosphere is presented as a novel route to obtain α-Fe and Fe3O4 magnetic nanoparticles dispersed in a MgO matrix. The phase composition, structural and magnetic properties, size and morphology of the nanoparticles were monitored by x-ray diffraction, 57Fe Mössbauer spectroscopy at temperatures of 24–300 K, transmission electron microscopy and magnetic measurements. Spherical magnetite nanoparticles prepared at a reaction temperature of 300 °C revealed a well-defined structure, with a ratio of tetrahedral to octahedral Fe sites of 1/2 being common for the bulk material. A narrow particle size distribution (20–30 nm) and high saturation magnetization (95 ± 5 A m2 kg−1) predispose the magnetite nanoparticles to various applications, including magnetic separation processes. The Verwey transition of Fe3O4 nanocrystals was found to be decreased to about 80 K. The deeper reduction of amorphous ferric oxide at 600 °C allows α-Fe (40–50 nm) nanoparticles to be synthesized with a coercive force of about 30 mT. They have a saturation magnetization 2.2 times higher than that of synthesized magnetite nanoparticles, which corresponds well with the ratio usually found for the pure bulk phases. The magnetic properties of α-Fe nanocrystals combined with the high chemical and thermal stability of the MgO matrix makes the prepared nanocomposite useful for various magnetic applications.

show abstract

“…A sharp increment of G' was observed for all samples due to reactions with oxygen. The latter behaviour can lead to inferior magnetic particles formation (iron oxidation), but such byproducts are formed at much higher temperatures 16 . In Fig.…”

Section: Rheology and Glass Transition Temperaturementioning

confidence: 99%

Reprocessed Magnetorheological Elastomers with Reduced Carbon Footprint and their Piezoresistive Properties

Sedlačík

Ronzová

Munteanu

et al. 2022

Preprint

View full text Add to dashboard Cite

Magnetorheological elastomers (MREs) are widely studied materials, however not many research papers have been initiated on their reprocessing. This paper presents a new type of recyclable MRE which is composed of thermoplastic polyurethane (TPU) and carbonyl iron particles (CI). The chosen TPU can be processed by injection moulding (IM) and allows several reprocessing cycles. Numerous types of injection moulded MREs, which have undergone several recycling cycles, have been prepared. The effect of thermo-mechanical degradation on the recycled MREs has been investigated. An apparent decrease in molecular weight of all examined matrices during reprocessing cycles was observed. These changes are attributed to the intermolecular bonding between the hydroxyl groups on the surface of the CI particles and the matrix. An evaluation of the mechanical properties of the matrices was conducted via tensile strength tests. Generally, MREs suffer from minor degradation due to reprocessing, yet the rheological and piezoresistivity properties are at an acceptable level despite using 100% of recyclates while in real applications only up to 30% of recycled material is used.

show abstract

Structural–chemical transformations of α-Fe2O3 upon transport reduction

Cited by 21 publications

References 1 publication

Combustion synthesis of zinc ferrite powders in oxygen

Combustion synthesis of zinc ferrite powders in oxygen

Novel solid-state synthesis of α-Fe and Fe₃O₄nanoparticles embedded in a MgO matrix

Reprocessed Magnetorheological Elastomers with Reduced Carbon Footprint and their Piezoresistive Properties

Contact Info

Product

Resources

About

Structural–chemical transformations of α-Fe2O3 upon transport reduction

Cited by 21 publications

References 1 publication

Combustion synthesis of zinc ferrite powders in oxygen

Combustion synthesis of zinc ferrite powders in oxygen

Novel solid-state synthesis of α-Fe and Fe3O4nanoparticles embedded in a MgO matrix

Reprocessed Magnetorheological Elastomers with Reduced Carbon Footprint and their Piezoresistive Properties

Contact Info

Product

Resources

About

Novel solid-state synthesis of α-Fe and Fe₃O₄nanoparticles embedded in a MgO matrix